UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 10-K

(Mark One)

[ X ] Annual Report Pursuant to Section 13 or 15(d) of the Securities
Exchange Act of 1934
For the fiscal year ended December 31, 1997
or
[ ] Transition Report Pursuant to Section 13 or 15(d) of the Securities
Exchange Act of 1934
For the transition period from to

Commission file number 1-7296

NORTHERN ILLINOIS GAS COMPANY
(Doing business as Nicor Gas Company)

(Exact name of registrant as specified in its charter)

            Illinois                                         36-2863847
(State or other jurisdiction of                           (I.R.S. Employer
 incorporation or organization)                         Identification No.)

             1844 Ferry Road
          Naperville, Illinois                                60563-9600
(Address of principal executive offices)                      (Zip Code)

Registrant's telephone number, including area code: (630) 983-8888

Securities registered pursuant to Sections 12(b) or 12(g) of the Act: None

The registrant meets the conditions set forth in General Instruction I(1)(a) and (b) of Form 10-K and is therefore filing this Form with the reduced disclosure format.

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months and (2) has been subject to such filing requirements for the past 90 days. Yes X No

Indicate by check mark if disclosure of delinquent filers pursuant to

Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. [ X ]

Shares of common stock, par value $5, outstanding at February 28, 1998, were 15,232,414 all of which are owned by Nicor Inc.

Nicor Gas Company Page i

Table of Contents

Item No.                                                                 Page
             Part I
    1.       Business...................................................    1

    2.       Properties.................................................    5

    3.       Legal Proceedings..........................................    5

    4.       Submission of Matters to a Vote of Security Holders........    *

             Part II
    5.       Market for Registrant's Common Equity and Related
               Stockholder Matters......................................    5

    6.       Selected Financial Data....................................    *

    7.       Management's Discussion and Analysis of Financial
               Condition and Results of Operations......................    6

   7A.       Quantitative and Qualitative Disclosures About Market Risk.   11

    8.       Financial Statements and Supplementary Data................   12

    9.       Changes in and Disagreements with Accountants on
               Accounting and Financial Disclosure......................   26

             Part III
   10.       Directors and Executive Officers of the Registrant.........    *

   11.       Executive Compensation.....................................    *

   12.       Security Ownership of Certain Beneficial Owners
               and Management...........................................    *

   13.       Certain Relationships and Related Transactions.............    *

             Part IV
   14.       Exhibits, Financial Statement Schedules, and Reports
               on Form 8-K..............................................   26

             Signatures.................................................   28

             Supplemental Information...................................   29

             Exhibit Index..............................................   30

Selected Terms:

FERC - Federal Energy Regulatory Commission.
Ill.C.C. - Illinois Commerce Commission.
Mcf, Bcf - Thousand cubic feet, billion cubic feet.
Degree days - The extent to which the daily average temperature falls below
                65 degrees Fahrenheit.

* The Registrant meets the conditions set forth in General Instruction I(1)(a) and (b) of Form 10-K and is therefore omitting the information called for by the otherwise required Item.

Nicor Gas Company Page 1

As part of Nicor Inc.'s plan to bring all of its energy-related businesses together under one name, Northern Illinois Gas began doing business as Nicor Gas in October 1997. Although Northern Illinois Gas continues to function as a legal entity, products and services are now marketed under a single common brand identity "Nicor." Northern Illinois Gas is hereinafter referred to as Nicor Gas.

PART I

Item 1. Business

Nicor Gas, an Illinois corporation formed in 1954, is a wholly owned subsidiary of Nicor Inc., a holding company.

GENERAL

Nicor Gas is one of the nation's largest natural gas distribution companies. The company delivers natural gas to about 1.9 million customers, including transportation service, gas storage and gas supply backup to approximately 22,000 commercial and industrial customers who purchase their own gas supplies. The company has approximately 2,200 employees. The company's service territory encompasses most of the northern third of Illinois, excluding the city of Chicago. Nicor Gas maintains franchise agreements with most of the communities it serves, allowing it to construct, operate and maintain distribution facilities in those communities. Franchise agreement terms range up to 50 years. Currently, less than 5 percent of the agreements will expire in five years or less.

Nicor Gas' service territory is diverse and has grown steadily over the years, providing the company with a well-balanced mix of residential, commercial and industrial customers. In 1997, residential customers accounted for over 40 percent of natural gas deliveries, while commercial and industrial customers accounted for approximately 25 percent and 35 percent, respectively. In addition, the company's industrial and commercial customer base is well-diversified, lessening the impact of industry-specific economic swings. See Operating Statistics on page 7 for operating revenues, deliveries and customers by customer classification.

Gas deliveries are seasonal since approximately 50 percent are used for space heating. Typically, 70 percent to 75 percent of deliveries and revenues occur from October through March.

CUSTOMER SERVICES

In addition to gas sales to all customer classes, Nicor Gas provides transportation service to commercial and industrial customers who purchase their own gas supplies. Transportation customers have options that include use of the company's storage system, the choice of individual or group billing, and the ability to choose varying supply backup levels and service options. The company receives a margin generally comparable to gas sales for transportation service with full supply backup.

Nicor Gas Company Page 2

Item 1. Business (continued)

In recent years, Nicor Gas has developed several nontraditional activities that are intended to maximize the value of the company's assets, expertise and customer base. These activities include: providing intrastate transportation service to neighboring pipelines and gas distribution companies; providing a variety of hub services to buyers and sellers of natural gas; providing natural gas storage services to customers; selling space for direct-mail inserts in customer bills; and providing water meter reading services to municipalities.

SOURCES OF GAS SUPPLY

Nicor Gas purchases gas supplies on a deregulated basis directly from producers and marketers. Pipeline transportation and purchased storage services are contracted for at rates regulated by the FERC.

Nicor Gas has been able to obtain sufficient supplies of natural gas to meet customer requirements. The company believes natural gas supply availability will be sufficient to meet market demands in the foreseeable future.

Gas supply. Nicor Gas maintains a diversified portfolio of gas supply contracts. Firm gas supply contracts are diversified by supplier, producing region, quantity, available transportation, contract length and contract expiration date. Contract pricing is generally tied to published price indices so as to approximate current market prices. The contracts also generally provide for the payment of fixed demand charges to ensure the availability of supplies on any given day. Contracts for about 70 percent of the volumes will expire in 1998, 25 percent in 1999 and the remainder by 2001.

The company also purchases gas supplies on the spot market to fulfill its supply requirements or to take advantage of favorable short-term pricing. Spot gas purchases accounted for 56 percent, 46 percent and 22 percent of the company's total gas purchased in 1997, 1996 and 1995, respectively.

Customers served under the company's transportation service tariffs purchase their own gas supplies. Approximately 40 percent of the gas that the company delivered in 1997 was purchased by transportation customers directly from producers and marketers rather than from the company.

Pipeline transportation and storage. Nicor Gas is directly connected to five interstate pipelines which provide access to most of the major natural gas producing regions in North America. The company's primary firm transportation contracts are with: Natural Gas Pipeline Company of America, which accounts for about two-thirds of the contracted capacity, Midwestern Gas Transmission Company and Northern Natural Gas Company. These contracts expire in the year 2000.

Nicor Gas Company Page 3

Item 1. Business (continued)

The company's peak day requirements are met through utilization of company- owned storage facilities, firm pipeline capacity, purchased storage services and other supply arrangements. The firm pipeline capacity and purchased storage services held by the company that are temporarily not needed can be released in the secondary market under FERC-mandated capacity release provisions, with proceeds reducing the company's cost of gas charged to customers.

Nicor Gas owns and operates seven underground gas storage facilities. This storage system is one of the largest in the gas distribution industry and is designed to meet about 55 percent of the company's peak day deliveries and approximately 30 percent of its normal winter deliveries. On an annual basis, the company cycles about 130 Bcf of gas through its storage fields. In addition to the company-owned facilities, Nicor Gas purchases about 40 Bcf of storage service. Storage provides supply flexibility, improves reliability of deliveries and reduces costs.

COMPETITION/DEMAND

Nicor Gas is one of the largest utility energy suppliers in Illinois, delivering about one-third of all utility energy consumed in the state. About 95 percent of all single-family homes in Nicor Gas' service territory are heated with natural gas. The company's gas services compete with other forms of energy, such as electricity and oil. Significant factors that impact demand for natural gas include weather, economic conditions and the price of gas relative to competitive fuels.

Over the last decade, federal and state regulatory changes in the energy industry have had a significant impact on the way utility companies operate. This trend continued in 1997 as Illinois adopted legislation that will direct the process of deregulating the state's electric utility industry. Although Nicor Gas' traditional pricing advantage compared to electricity may decrease as the price of electricity declines, the company expects to maintain a pricing advantage in the foreseeable future.

Additional information on competition and demand is presented in Item 7, Management's Discussion and Analysis of Financial Condition and Results of Operations, on pages 9 through 11.

REGULATION

Nicor Gas is regulated by the Ill.C.C. which establishes the rules and regulations governing utility rates and services in Illinois. Rates are designed to allow the company to recover its costs and provide an opportunity to earn a fair return for its investors.

The cost of gas the company purchases for customers is recovered through a monthly gas supply charge, which accounts for approximately 70 percent of a typical residential customer's annual bill. The company's cost of gas is passed on to the customer with no markup.

Nicor Gas Company Page 4

Item 1. Business (concluded)

In 1997, the Ill.C.C. approved Nicor Gas' plans for a three-year test program called Customer SelectSM that will give more customers the opportunity to choose their natural gas supplier. Additional information on the test program is presented in Item 7, Management's Discussion and Analysis of Financial Condition and Results of Operations, on page 11.

In April 1996, the Ill.C.C. granted Nicor Gas a 2.8 percent, $33.7 million general rate increase. For further information relating to that item, see Rate Order on page 20.

ENVIRONMENTAL MATTERS

Information with respect to environmental matters is presented in the Contingencies section of the Notes to the Consolidated Financial Statements on page 24.

Nicor Gas Company Page 5

Item 2. Properties

The company's properties are located in the territory described under Item 1, Business, and are suitable, adequate and utilized in its operations.

The gas distribution, transmission and storage system includes approximately 29,000 miles of steel, plastic and cast iron main; approximately 26,000 miles of steel, plastic/aluminum composite, plastic and copper service pipe connecting the mains to customers' premises; and seven underground storage fields. Other properties include buildings, land, motor vehicles, meters, regulators, compressors, construction equipment, tools, and communication, computer and office equipment.

The principal real properties are held under easements, permits, licenses or in fee. Land in fee is owned for essentially all administrative offices and for certain transmission mains and underground storage fields. Substantial- ly all properties are subject to the lien of the indenture securing the company's first mortgage bonds.

Item 3. Legal Proceedings

For information concerning legal proceedings, see Rate Order on page 20 and Contingencies on page 24 in Notes to the Consolidated Financial Statements, which are incorporated herein by reference.

PART II

Item 5. Market for Registrant's Common Equity and Related Stockholder Matters

All of the outstanding common stock of Nicor Gas is owned by Nicor Inc. There is no public trading market for the company's common stock. During 1997 and 1996, the company declared quarterly common dividends totaling $107.5 million and $124.1 million, respectively.

Nicor Gas Company Page 6

Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations

The purpose of this financial review is to explain changes in Nicor Gas' operating results and financial condition from 1995 to 1997. This review also discusses business trends and uncertainties that might affect Nicor Gas. Certain terms used herein are defined in the Table of Contents.

RESULTS OF OPERATIONS

Net income for 1997 of $106.9 million was essentially unchanged from 1996. Positive factors during the year included lower operating and maintenance expenses, additional gains from property sales and the positive impact of tax-related matters. Negative factors included lower deliveries due, in part, to weather that was 3 percent warmer than the prior year and the carryover impact of rate design changes and a depreciation rate increase implemented as part of an April 1996 general rate increase. The rate design changes had a positive impact on 1996 results but a negative impact on first quarter 1997 results. For further information on the general rate increase, see Rate Order on page 20. In 1996, net income increased $21.7 million to $107.1 million as the impact of the general rate increase and an increase in deliveries of natural gas more than offset higher depreciation. Higher deliveries were attributable to the positive impact of weather that was 5 percent colder than in 1995, demand growth among existing customers and customer additions.

Operating revenues. Operating revenues of $1,730.5 million were up 7 percent because of higher natural gas supply costs which are recovered from customers. In 1996, operating revenues of $1,610.2 million were up 23 percent due to the recovery from customers of higher gas costs, an increase in deliveries and the impact of the rate order.

Margin. Margin, defined as operating revenues less cost of gas and revenue taxes, which are both passed directly through to customers, declined $6.5 million to $496 million in 1997 due to warmer weather and the negative first quarter impact of the 1996 rate order. In 1996, margin rose $60.2 million to $502.5 million due primarily to the positive effect of the rate order and higher deliveries. Margin per Mcf delivered in 1996 rose primarily as a result of the rate order.

Operating and maintenance. In 1997, operating and maintenance expenses decreased 4 percent to $150.8 million. The decrease was due, in part, to lower payroll and retirement benefits costs, which more than offset a higher provision for uncollectible accounts. Favorable pension fund investment returns contributed to the reduction in retirement benefits costs.

Depreciation. Depreciation rose 4 percent in 1997 to $116.6 million and 13 percent in 1996 to $111.8 million due to the change in the composite depreciation rate and plant additions. For further information on the change in the composite depreciation rate, see Accounting Policies on page 19.

Other income. Other income increased $3.7 million in 1997 to $5.4 million due to gains from property sales. In 1996, other income decreased $.5 million to $1.7 million as the impact of lower investment levels on interest income more than offset gains from property sales.

Nicor Gas Company Page 7

Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations (continued)

In 1997, Nicor Gas entered into agreements to sell certain nonutility properties at a gain of about $11 million. Approximately one-half of the gain was recognized in 1997. The remaining gain is expected to be recorded upon sale closings in the first half of 1998. The company is assessing its nonstrategic real estate holdings, and there may be potential to maximize the value of these holdings through additional property sales or development over the next several years.

Interest expense. In 1996, interest expense rose $8.1 million to $47 million due primarily to higher borrowing levels.

Operating Statistics
                                                   1997           1996             1995

Operating revenues (Millions)
  Sales
    Residential                                 $ 1,126.0      $ 1,040.2        $   849.8
    Commercial                                      314.8          281.9            217.8
    Industrial                                       56.8           54.4             35.9
                                                  1,497.6        1,376.5          1,103.5
  Transportation
    Commercial                                       55.3           55.7             50.3
    Industrial                                       48.4           54.0             62.5
                                                    103.7          109.7            112.8
  Revenue taxes and other                           129.2          124.0             96.4

                                                $ 1,730.5      $ 1,610.2        $ 1,312.7

Deliveries (Bcf)
  Sales
    Residential                                     233.2          247.0            231.4
    Commercial                                       65.2           67.0             59.3
    Industrial                                       12.9           15.0             10.5
                                                    311.3          329.0            301.2
  Transportation
    Commercial                                       66.0           73.5             64.0
    Industrial                                      168.0          154.1            165.6
                                                    234.0          227.6            229.6

                                                    545.3          556.6            530.8

Year-end customers (Thousands)
  Sales
    Residential                                   1,710.0        1,688.5          1,660.6
    Commercial                                      143.0          142.1            141.7
    Industrial                                       11.1           11.6             11.6
                                                  1,864.1        1,842.2          1,813.9
  Transportation
    Commercial                                       18.7           18.1             17.1
    Industrial                                        3.0            2.7              2.5
                                                     21.7           20.8             19.6

                                                  1,885.8        1,863.0          1,833.5

Nicor Gas Company Page 8

Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations (continued)

FINANCIAL CONDITION AND LIQUIDITY

The company believes it has access to adequate resources to meet planned capital expenditures, debt redemptions, dividends and working capital needs. These resources include net cash flow from operating activities, access to capital markets and unused lines of credit.

Operating. Net cash flow from operating activities was $204.3 million in 1997, $45.6 million in 1996 and $254.1 million in 1995. The 1997 increase was due primarily to the timing of gas cost recoveries. The 1996 decrease was due to the impact of increased gas in storage, the timing of the recovery of gas costs from customers, a 1995 gas pipeline refund and a return to normal levels of customer advance payments.

The working capital component of net cash flow from operating activities can swing sharply due primarily to certain factors including weather, the timing of collections from customers and gas purchasing practices. The company generally relies on short-term financing to meet temporary increases in working capital needs.

Investing. Capital expenditures were $101.8 million in 1997 compared with $107.7 million in 1996 and $152.2 million in 1995. Capital expenditures were higher in 1995 because of costs relating to a major transmission and storage system improvement project. Reduced 1997 and 1996 capital expenditures also reflect continuing cost management efforts.

Capital spending in 1998 is projected to be about $135 million. Included in this amount are costs to commence replacement of the customer information and billing system that is scheduled to be in operation in the year 2000.

Financing. Long-term debt as a percent of capitalization was 43 percent, 41.7 percent and 38.6 percent at year-end 1997, 1996 and 1995, respectively. The company's ratio of earnings to fixed charges was 4.7, 4.7, and 4.4 for the years ended December 31, 1997, 1996 and 1995, respectively.

Long-term debt. In December 1997, Nicor Gas filed a $175 million First Mortgage Bond shelf registration statement with the Securities and Exchange Commission. The net proceeds from any securities issued are expected to be used for the refinancing of certain debt.

In October 1997, Nicor Gas issued $50 million of 7-3/8% First Mortgage Bonds due in 2027, which represented the remaining $50 million of a 1994 shelf registration statement. The net proceeds from the sale of the bonds were used, together with other corporate funds, for the November 1997 retirement of $50 million of 9% First Mortgage Bonds due in 2019.

In June 1997, Nicor Gas issued $50 million of 6-3/4% First Mortgage Bonds due in 2002. The net proceeds from the sale of the bonds replenished corporate funds used for the February 1997 maturity of $25 million of 5-1/2% First Mortgage Bonds and for general corporate purposes.

Nicor Gas Company Page 9

Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations (continued)

In August 1996, Nicor Gas sold $75 million of 6.45% First Mortgage Bonds due in 2001. The net proceeds from the sale of the bonds replenished corporate funds used for the March 1996 maturity of $50 million of 4-1/2% First Mortgage Bonds and for general corporate purposes.

In October 1995, Nicor Gas issued $50 million of 7.26% First Mortgage Bonds due in 2025. The net proceeds of the sale replenished corporate funds used for the maturity of $50 million of 5-1/2% unsecured notes due in July 1995.

Short-term debt. Nicor Gas maintains short-term credit agreements with major domestic and foreign banks. At December 31, 1997, these agreements, which serve as backup for the issuance of commercial paper, totaled $250 million. The company had $254.4 million and $273 million of commercial paper outstanding at year-end 1997 and 1996, respectively.

Common and preferred stock. The company paid dividends of $109.1 million, $91.8 million and $71.4 million in 1997, 1996 and 1995, respectively.

FACTORS AFFECTING BUSINESS PERFORMANCE

The following factors can impact year-to-year comparisons and may affect the future performance of Nicor Gas.

Nicor Gas serves about 1.9 million customers in a service territory that encompasses most of the northern third of Illinois, excluding the city of Chicago. The region's economy is diverse and has grown steadily over the years, providing Nicor Gas with a well-balanced mix of residential, commercial and industrial customers. In 1997, residential customers accounted for over 40 percent of natural gas deliveries, while commercial and industrial customers accounted for approximately 25 percent and 35 percent, respectively.

Since about one-half of gas deliveries are used for space heating, fluctuations in weather can have a significant impact on year-to-year comparisons of operating income and cash flow. In addition, significant changes in gas prices or economic conditions can impact gas usage. However, Nicor Gas' large residential customer base provides relative stability during weak economic periods. Also, the industrial and commercial customer base is well-diversified, lessening the impact of industry-specific economic swings.

Nicor Gas competes with other energy suppliers based on such factors as price, service and reliability. The company is well-positioned to deal with the possibility of fuel switching by customers because it has rates and services designed to compete against alternative fuels and because of its competitively priced supply of gas. In addition, the company has a rate which allows negotiation with potential bypass customers, and no customer has bypassed since the rate became effective in 1987. Nicor Gas also offers commercial and industrial customers flexibility and alternatives in rates and service, increasing its ability to compete in these markets.

Nicor Gas Company Page 10

Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations (continued)

Direct connection to five interstate pipelines and extensive underground storage capacity allow the company to maintain rates that are among the lowest in the nation, while also providing transportation customers with direct access to gas supplies and storage services. In addition, in an effort to ensure supply reliability, the company purchases gas from several different producing regions under varied contract terms.

Operating Statistics
                                                      1997          1996          1995

Year-end customers (Thousands)                       1,885.8       1,863.0       1,833.5
Margin (Millions)                                    $ 496.0       $ 502.5       $ 442.3
Deliveries (Bcf)                                       545.3         556.6         530.8
Margin per Mcf delivered                             $   .91       $   .90       $   .83
Average gas cost per Mcf sold                        $  3.54       $  2.99       $  2.52
Degree days (Normal 6,116)                             6,254         6,429         6,111

Nicor Gas' growth in deliveries has typically come from a combination of customer additions and increased usage among existing customers. The company anticipates continued steady growth in its customer base and will continue to promote the use of natural gas for diversified uses such as cogeneration and large-tonnage gas air conditioning. In addition, the company expects that an abundant supply of natural gas at competitive prices will encourage additional gas-fired electric power generation.

While working to achieve growth in its traditional gas distribution operations, Nicor Gas has also been pursuing several nontraditional activities. These nontraditional activities include: providing intrastate transportation service to neighboring pipelines and gas distribution companies; providing a variety of hub services to buyers and sellers of natural gas; providing natural gas storage services to customers; selling space for direct-mail inserts in customer bills; and providing water meter reading services to municipalities.

Nicor Gas is regulated by the Ill.C.C. which establishes the rules and regulations governing utility rates and services in Illinois. Rates are designed to allow the company to recover its costs and provide an opportunity to earn a fair return for its investors. Changes in the regulatory environment could affect the longer-term performance of Nicor Gas.

Over the last decade, federal and state regulatory changes in the energy industry have had a significant impact on the way utility companies operate. This trend continued in 1997 as Illinois adopted legislation that will direct the process of deregulating the state's electric utility industry. The new legislation calls for rate cuts in 1998 and again in 2002 for most electric utility customers. Customer choice and competition will be phased in over several years, beginning with commercial and industrial customers in 1999, then adding residential customers in 2002. Although Nicor Gas' traditional pricing advantage compared to electricity may decrease as the

Nicor Gas Company Page 11

Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations (concluded)

price of electricity declines, the company expects to maintain a pricing advantage in the foreseeable future. Ongoing efforts to maintain this pricing advantage include: continuing to reduce fixed gas supply and pipeline transportation costs; reducing operating and maintenance expenses while increasing customer satisfaction; and reducing capital spending from historic levels while maintaining system integrity.

In 1997, the Ill.C.C. approved Nicor Gas' plans for a three-year test program called Customer SelectSM that will give more customers the opportunity to choose their natural gas supplier. Currently over 10 percent of the company's commercial and industrial customers purchase natural gas from other suppliers. In the Customer Select test program, the remaining 150,000 commercial and industrial customers will be eligible to choose their suppliers. In the first year, as many as 20,000 of those customers will be allowed to enroll in the program. In the year 2000, up to 10,000 residential customers will also be allowed to enroll.

Year 2000. Nicor Gas has identified systems which may be affected by the "Year 2000" issue and has developed a plan that encompasses replacement or modification of existing applications and communication with major suppliers, customers and other parties. Nicor Gas does not expect the "Year 2000" issue to have a material impact on its financial position or results of operations.

Contingencies. The company is conducting environmental investigations and remedial activities at former gas manufacturing plant sites. Although unable to determine the outcome of these contingencies, management believes that appropriate accruals have been recorded. Final disposition of these matters is not expected to have a material impact on the company's financial condition or results of operations. For further information, see Contingencies on page 24.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

Not applicable.

Nicor Gas Company                                                    Page 12

Item 8.  Financial Statements and Supplementary Data

                                                                      Page

Report of Independent Public Accountants                               13

Financial Statements:

  Consolidated Statement of Income                                     14

  Consolidated Statement of Cash Flows                                 15

  Consolidated Balance Sheet                                           16

  Consolidated Statement of Capitalization                             17

  Consolidated Statement of Retained Earnings                          18

  Notes to the Consolidated Financial Statements                       19

Nicor Gas Company Page 13

Report of Independent Public Accountants

To Northern Illinois Gas Company (Doing business as Nicor Gas Company):

We have audited the accompanying consolidated balance sheet and statement of capitalization of Nicor Gas Company (an Illinois corporation and a wholly owned subsidiary of Nicor Inc.) and subsidiary company as of December 31, 1997 and 1996, and the related consolidated statements of income, retained earnings and cash flows for each of the three years in the period ended December 31, 1997. These financial statements and the schedule referred to below are the responsibility of the company's management. Our responsibili- ty is to express an opinion on these financial statements and the schedule based on our audits.

We conducted our audits in accordance with generally accepted auditing standards. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial position of Nicor Gas Company and subsidiary company as of December 31, 1997 and 1996, and the results of their operations and their cash flows for each of the three years in the period ended December 31, 1997, in conformity with generally accepted accounting principles.

Our audits were made for the purpose of forming an opinion on the basic financial statements taken as a whole. The financial statement schedule listed in the accompanying index (page 26) is presented for purposes of complying with the Securities and Exchange Commission's rules and is not part of the basic financial statements. This schedule has been subjected to the auditing procedures applied in the audits of the basic financial statements and, in our opinion, fairly states in all material respects the financial data required to be set forth therein in relation to the basic financial statements taken as a whole.

ARTHUR ANDERSEN LLP

Chicago, Illinois
January 27, 1998

Nicor Gas Company                                                                                                      Page 14

Consolidated Statement of Income
(Millions)

                                                                                               Year Ended December 31
                                                                                     1997               1996               1995

Operating revenues                                                                $ 1,730.5          $ 1,610.2          $ 1,312.7

Operating expenses
  Cost of gas                                                                       1,129.0            1,008.9              787.2
  Operating and maintenance                                                           150.8              156.6              155.1
  Depreciation                                                                        116.6              111.8               98.8
  Taxes, other than income taxes                                                      124.0              117.4              100.9
  Income taxes                                                                         61.5               63.1               48.6
                                                                                    1,581.9            1,457.8            1,190.6

Operating income                                                                      148.6              152.4              122.1

Other income (expense)
  Interest income                                                                       1.4                 .1                2.5
  Other, net                                                                            7.2                2.1                1.0
  Income taxes on other income                                                         (3.2)               (.5)              (1.3)
                                                                                        5.4                1.7                2.2

Interest expense
  Interest on debt, net of amounts capitalized                                         45.9               44.4               38.1
  Other                                                                                 1.2                2.6                 .8
                                                                                       47.1               47.0               38.9

Net income                                                                            106.9              107.1               85.4

Dividends on preferred stock                                                             .4                 .5                 .5

Earnings applicable to common stock                                               $   106.5          $   106.6          $    84.9

<F1>
Nicor Gas is a wholly owned subsidiary of Nicor Inc.  Earnings and dividends per share information
is therefore omitted.
<F2>
The accompanying notes are an integral part of this statement.

Nicor Gas Company                                                                                               Page 15

Consolidated Statement of Cash Flows
(Millions)
                                                                                               Year Ended December 31
                                                                                     1997               1996               1995

Operating activities
  Net income                                                                       $ 106.9            $ 107.1            $  85.4
  Adjustments to reconcile net income to net
     cash flow provided from operating activities:
       Depreciation                                                                  116.6              111.8               98.8
       Deferred income tax expense (benefit)                                           8.2                (.9)               5.0
       Change in working capital items and other:
          Accounts receivable, less allowances                                       (17.8)             (60.8)             (40.6)
          Gas in storage                                                               3.8              (55.2)               7.0
          Deferred/accrued gas costs                                                  76.2              (42.4)              25.9
          Accounts payable                                                           (77.5)              10.5               50.3
          Gas refunds due customers                                                    1.0              (22.9)              21.9
          Other                                                                      (13.1)              (1.6)                .4

  Net cash flow provided from operating activities                                   204.3               45.6              254.1

Investing activities
  Capital expenditures                                                              (101.8)            (107.7)            (152.2)
  Other                                                                               10.8                1.9                 .3

  Net cash flow used for investing activities                                        (91.0)            (105.8)            (151.9)

Financing activities
  Net proceeds from issuing long-term debt                                            99.1               74.2               49.5
  Disbursements to retire long-term debt                                             (77.6)             (50.0)             (50.0)
  Short-term borrowings (repayments), net                                            (29.6)             132.6              (36.6)
  Dividends paid                                                                    (109.1)             (91.8)             (71.4)
  Other                                                                                (.5)               (.4)               (.5)

  Net cash flow provided from (used for) financing
     activities                                                                     (117.7)              64.6             (109.0)

Net increase (decrease) in cash and cash equivalents                                  (4.4)               4.4               (6.8)

Cash and cash equivalents, beginning of year                                           4.4                  -                6.8

Cash and cash equivalents, end of year                                             $     -            $   4.4            $     -

Supplemental information
  Income taxes paid, net of refunds                                                $  56.1            $  66.9            $  45.0
  Interest paid, net of amounts capitalized                                           47.3               51.8               38.3

<F1>
The accompanying notes are an integral part of this statement.

Nicor Gas Company                                                                                    Page 16

Consolidated Balance Sheet
(Millions)
                                                                                                           December 31
                          Assets                                                                   1997                  1996

Gas distribution plant, at cost                                                                 $ 3,012.3             $ 2,942.8
  Less accumulated depreciation                                                                   1,382.3               1,280.9

                                                                                                  1,630.0               1,661.9

Other property and investments, net of accumulated
  depletion of $14.5                                                                                  4.3                   8.8

Current assets
  Cash and cash equivalents                                                                             -                   4.4
  Accounts receivable, less allowances of $7.6
     and $6.1, respectively                                                                         321.4                 303.6
  Gas in storage, at last-in, first-out cost                                                        127.8                 118.2
  Deferred gas costs                                                                                    -                  51.1
  Other                                                                                              22.0                  28.2

                                                                                                    471.2                 505.5

Other assets                                                                                         83.7                  69.0

                                                                                                $ 2,189.2             $ 2,245.2

               Capitalization and Liabilities

Capitalization
  Long-term debt                                                                                $   520.9             $   495.5
  Preferred stock                                                                                     9.5                  10.0
  Common equity                                                                                     681.4                 682.4

                                                                                                  1,211.8               1,187.9

Current liabilities
  Long-term obligations due within one year                                                          25.5                  25.5
  Short-term borrowings                                                                             254.6                 284.2
  Accounts payable                                                                                  214.0                 291.5
  Accrued interest                                                                                   30.9                  31.9
  Dividends payable                                                                                  31.7                  32.9
  Other                                                                                              44.0                  17.8

                                                                                                    600.7                 683.8

Deferred credits and other liabilities
  Deferred income taxes                                                                             184.6                 179.5
  Regulatory income tax liability                                                                    81.7                  83.8
  Unamortized investment tax credits                                                                 46.2                  48.4
  Other                                                                                              64.2                  61.8

                                                                                                    376.7                 373.5

                                                                                                $ 2,189.2             $ 2,245.2

<F1>
The accompanying notes are an integral part of this statement.

Nicor Gas Company                                                                                    Page 17

Consolidated Statement of Capitalization
(Millions, except share data)
                                                                                             December 31
                                                                                  1997                            1996

Long-term debt
  First mortgage bonds
     Maturity                  Interest rate
       1997                        5.50 %                                $       -                       $    25.0
       1998                        5.875                                      25.0                            25.0
       1999                        6.25                                       25.0                            25.0
       2000                        5.875                                      50.0                            50.0
       2001                        6.45                                       75.0                            75.0
       2002                        6.75                                       50.0                               -
       2019                        9.0                                           -                            50.0
       2021                        8.875                                      50.0                            50.0
       2022                        8.25                                       75.0                            75.0
       2023                        7.375                                      50.0                            50.0
       2024                        8.25                                       50.0                            50.0
       2025                        7.26                                       50.0                            50.0
       2027                        7.375                                      50.0                               -
                                                                             550.0                           525.0
  Less:  Amount due within one year                                           25.0                            25.0
         Unamortized debt discount, net of premium                             4.1                             4.5

                                                                             520.9        43.0%              495.5        41.7%

Preferred stock, cumulative, $100 par value, 800,000
  shares authorized
     Redeemable preferred stock, 4.48% and 5.00% series,
       60,000 and 26,000 shares outstanding, respectively,
       in 1997, and 63,000 and 28,000 shares outstanding,
       respectively, in 1996                                                   8.6                             9.1
     Less amount due within one year                                            .5                              .5
                                                                               8.1          .7                 8.6          .7

     Nonredeemable preferred stock, 4.60% and 5.00%
       convertible series, 8,750 and 5,258 shares
       outstanding, respectively, in 1997 and 1996                             1.4          .1                 1.4          .1

Common equity
  Common stock, $5 par value, 25,000,000 shares authorized
     (32,365 shares reserved for conversion), 15,232,414
     shares outstanding                                                       76.1                            76.1
  Paid-in capital                                                            107.9                           107.9
  Retained earnings                                                          497.4                           498.4

                                                                             681.4        56.2               682.4        57.5

                                                                         $ 1,211.8       100.0%          $ 1,187.9       100.0%

<F1>
The accompanying notes are an integral part of this statement.

Nicor Gas Company                                                                                    Page 18

Consolidated Statement of Retained Earnings
(Millions)
                                                                                                Year Ended December 31
                                                                                       1997              1996              1995

Balance at beginning of year                                                         $ 498.4           $ 516.0           $ 502.0

Net income                                                                             106.9             107.1              85.4
Dividends declared on common stock                                                    (107.5)           (124.1)            (70.9)
Dividends declared on preferred stock                                                    (.4)              (.6)              (.5)

Balance at end of year                                                               $ 497.4           $ 498.4           $ 516.0

<F1>
The accompanying notes are an integral part of this statement.

Nicor Gas Company Page 19

Notes to the Consolidated Financial Statements

Nicor Gas is one of the nation's largest natural gas distributors, serving about 1.9 million customers in a service territory that encompasses most of the northern third of Illinois, excluding the city of Chicago.

ACCOUNTING POLICIES

General. Nicor Gas is a wholly owned subsidiary of Nicor Inc. Nicor Gas and its affiliates reimburse each other for transactions between the companies.

Consolidation. The consolidated financial statements include the accounts of Nicor Gas and its subsidiary. All significant intercompany balances and transactions have been eliminated. The preparation of the consolidated financial statements requires management to make estimates that affect the reported amounts. Actual results could differ from those estimates. Certain reclassifications were made to conform the prior years' financial statements to the current year presentation.

Regulation. Nicor Gas is regulated by the Ill.C.C. which establishes the rules and regulations governing utility rates and services in Illinois. The company applies accounting standards that recognize the economic effects of rate regulation and, accordingly, has recorded regulatory assets and liabilities. The company had net regulatory liabilities of about $100 million and $25 million at December 31, 1997 and 1996, respectively.

Operating revenues and gas costs. The cost of gas purchased, adjusted for inventory activity, is reflected in volumetric charges to customers through operation of the Uniform Purchased Gas Adjustment Clause (PGA). Any difference between PGA revenues and recoverable gas costs is deferred or accrued with a corresponding decrease or increase to cost of gas. This difference is amortized as it is collected from or refunded to customers through the PGA.

Depreciation. Property, plant and equipment are depreciated over estimated useful lives on a straight-line basis. In April 1996, the composite depreciation rate was increased to 4.1 percent from 3.7 percent.

Income taxes. Deferred income taxes are provided for temporary differences between the tax basis of an asset or liability and its reported amount in the financial statements. Although the federal investment tax credit has been eliminated, Nicor Gas continues to amortize prior deferred amounts to income over the lives of the applicable properties.

Cash and cash equivalents. The company considers investments purchased with a maturity of three months or less to be cash equivalents.

Receivable credit risk. The company has a diversified customer base and prudent credit policies which mitigate risk.

Nicor Gas Company Page 20

Notes to the Consolidated Financial Statements (continued)

RATE ORDER

Effective April 1996, the Ill.C.C. granted Nicor Gas a $33.7 million general rate increase, of which $12 million relates to a change in the company's composite depreciation rate. The new rate structure allows Nicor Gas to recover a larger proportion of its fixed costs during warmer months. The overall result is that the company's earnings are now less sensitive to the effects of weather, and seasonal variations in quarterly earnings are now reduced. In June 1997, the order was upheld by the Third District Appellate Court of Illinois and is now final.

GAS IN STORAGE

Based on the average cost of gas purchased in December 1997 and 1996, the estimated replacement cost of gas in inventory at December 31, 1997 and 1996, exceeded the last-in, first-out cost by $194.6 million and $351.5 million, respectively.

INCOME TAXES

The components of income tax expense are presented below:
(Millions)                                      1997          1996          1995

Current
  Federal                                      $ 48.8        $ 55.8        $ 40.1
  State                                           9.9          11.1           7.5
                                                 58.7          66.9          47.6
Deferred
  Federal                                         6.0          (1.8)          3.2
  State                                           2.2            .9           1.8
                                                  8.2           (.9)          5.0
Amortization of investment
  tax credits, net                               (2.2)         (2.4)         (2.7)

Income tax expense                             $ 64.7        $ 63.6        $ 49.9

Nicor Gas Company Page 21

Notes to the Consolidated Financial Statements (continued)

The temporary differences which gave rise to the net deferred tax liability at December 31, 1997 and 1996, were as follows:

(Millions)                                            1997             1996

Deferred tax liabilities
  Property, plant and equipment                     $  232.1        $  236.4
  Other                                                 14.4             9.4
                                                       246.5           245.8
Deferred tax assets
  Unamortized investment tax credits                    30.4            31.8
  Regulatory income tax liability                       20.4            20.6
  Other                                                 23.5            32.2
                                                        74.3            84.6

Net deferred tax liability                          $  172.2        $  161.2

The effective combined federal and state income tax rate was 37.7 percent, 37.2 percent and 36.9 percent in 1997, 1996 and 1995, respectively. Differences between federal income taxes computed using the statutory rate and reported income tax expense are shown below:

(Millions)                                             1997        1996       1995

Federal income taxes using
  statutory rate                                     $  60.1     $  59.7    $  47.4
State income taxes, net                                  8.2         7.9        6.7
Other, net                                              (3.6)       (4.0)      (4.2)

Income tax expense                                   $  64.7     $  63.6    $  49.9

POSTRETIREMENT BENEFITS

Pension benefits. Nicor Gas maintains noncontributory defined benefit pension plans covering substantially all employees. Pension benefits consider job level or the highest average salary earned during five consecutive years of employment and years of service. The plans are generally funded to the extent deductible for federal income tax purposes. Plan assets are invested primarily in corporate and government securities.

Net periodic pension cost (benefit) included:
(Millions)                                            1997          1996          1995

Service cost                                        $    6.5      $    7.7      $   6.4
Interest cost                                           17.6          19.8         19.3
Loss (return) on plan assets                           (83.5)        (61.9)       (61.5)
Net amortization and deferral                           46.9          26.8         27.0

                                                    $  (12.5)     $   (7.6)     $  (8.8)

Expected long-term rate of return
  on plan assets                                         8.5%          8.5%         9.0%

Nicor Gas Company Page 22

Notes to the Consolidated Financial Statements (continued)

The following table reflects the funded status of the pension plans at October 1, 1997 and 1996, reconciled to amounts recorded in the financial statements at December 31, 1997 and 1996, respectively:

(Millions)                                                      1997          1996

Vested benefits                                               $  172.6      $  192.6
Nonvested benefits                                                22.6          21.4
Accumulated benefit obligation                                   195.2         214.0
Effect of assumed increase in
  compensation level                                              28.7          31.3
Projected benefit obligation                                     223.9         245.3
Plan assets at market value                                      422.6         381.9
Plan assets in excess of projected
  benefit obligation                                             198.7         136.6
Unrecognized net gain                                           (118.5)        (64.5)
Unrecognized net transition asset                                (16.3)        (20.1)
Unrecognized prior service cost                                    3.7           4.1
Other                                                              3.2           1.9

Prepaid pension cost                                          $   70.8      $   58.0

Discount rate                                                      7.5%          7.5%
Rate of compensation increase                                      5.0           5.0

Nicor Gas has historically amended the collectively bargained pension plan every three years so that pension benefits are based on the most current wages. Nicor Gas intends, subject to collective bargaining, to continue making similar amendments to the plan. These future amendments have been anticipated and are reflected in the projected benefit obligation and pension expense.

Other postretirement benefits. Health care and life insurance benefits are provided for retired employees if they become eligible for retirement while working for Nicor Gas. The plans are generally funded to the extent deductible for federal income tax purposes. Plan assets are invested primarily in corporate and government securities.

Net periodic postretirement benefit cost included:
(Millions)                                                1997        1996         1995

Service cost                                            $   1.7     $   2.6      $   2.3
Interest cost                                               8.3         9.0          9.0
Loss (return) on plan assets                               (3.2)       (1.6)        (1.8)
Amortization of transition obligation                       3.3         3.7          3.7
Net amortization and deferral                               2.0          .5          1.0

                                                        $  12.1     $  14.2      $  14.2

Expected long-term rate of return
  on plan assets                                            8.5%        8.5%         9.0%

Nicor Gas Company Page 23

Notes to the Consolidated Financial Statements (continued)

The following table reflects the funded status of the postretirement health
care and life insurance plans at October 1, 1997 and 1996, reconciled to
amounts recorded in the financial statements at December 31, 1997 and 1996,
respectively:
(Millions)                                                    1997             1996

Accumulated postretirement benefit
  obligation (APBO):
     Retirees                                              $    85.1        $    79.2
     Fully eligible active plan participants                     8.3             12.0
     Other active plan participants                             21.6             23.0
Total APBO                                                     115.0            114.2
Plan assets at market value                                     16.6             13.4
APBO in excess of plan assets                                  (98.4)          (100.8)
Unrecognized transition obligation                              46.3             52.6
Unrecognized net loss                                            4.1              4.1
Other                                                           (1.6)             (.6)

Accrued postretirement benefit cost                        $   (49.6)       $   (44.7)

Discount rate                                                    7.5%             7.5%
Rate of compensation increase                                    5.0              5.0

The health care cost trend rate for pre-Medicare benefits was assumed to be 8 percent for 1998, declining to 5 percent by 2001 and remaining at that level thereafter. The health care cost trend rate for post-Medicare benefits was assumed to be 5 percent. Increasing the assumed health care cost trend rate by 1 percentage point would increase the APBO as of December 31, 1997, by about $12 million, the aggregate of the service and interest cost components of 1997 net postretirement health care costs by $1.4 million, and operating expense by $1 million, after capitalization.

SHORT- AND LONG-TERM DEBT

The company maintains short-term credit agreements with major domestic and foreign banks. These agreements, which serve as backup for the issuance of commercial paper, totaled $250 million at December 31, 1997. Commitment fees of up to .07 percent per annum were paid on these lines. All credit agreements have variable interest rate options tied to short-term markets.

The company had $254.4 million and $273 million of commercial paper outstanding with a weighted average interest rate of 5.96 percent and 5.36 percent at December 31, 1997 and 1996, respectively.

Bank cash balances averaged about $3 million during 1997, which partially compensated for the cost of maintaining accounts and other banking services. Such demand balances may be withdrawn at any time.

First mortgage bonds are secured by liens on substantially all gas distribution property and franchises.

Interest on debt was net of amounts capitalized of $.9 million in 1995.

Nicor Gas Company Page 24

Notes to the Consolidated Financial Statements (continued)

FAIR VALUE OF FINANCIAL INSTRUMENTS

The recorded amount of short-term borrowings approximates fair value because of the short maturity of the instruments. Based on quoted market interest rates, the recorded amount of the long-term debt outstanding, including current maturities, also approximates fair value.

CONTINGENCIES

The company is involved in legal or administrative proceedings before various courts and agencies with respect to rates, taxes and other matters.

Current environmental laws may require cleanup of certain former manufactured gas plant sites. To date, Nicor Gas has identified about 40 properties for which it may, in part, be responsible. The majority of these properties are not presently owned by the company. Information regarding preliminary site reviews has been presented to the Illinois Environmental Protection Agency. More detailed investigations and remedial activities are either in progress or planned at many of these sites. The results of continued testing and analysis should determine to what extent additional remediation is necessary and may provide a basis for estimating any additional future costs which, based on industry experience, could be significant. In accordance with Ill.C.C. authorization, the company has been recovering these costs from its customers.

On December 20, 1995, Nicor Gas filed suit in the Circuit Court of Cook County against certain insurance carriers seeking recovery of environmental cleanup costs of certain former manufactured gas plant sites. Presently, management cannot predict the outcome of this lawsuit. Any recoveries from such litigation or other sources will be flowed back to the company's customers.

Although unable to determine the outcome of these contingencies, management believes that appropriate accruals have been recorded. Final disposition of these matters is not expected to have a material impact on the company's financial condition or results of operations.

Nicor Gas Company Page 25

Notes to the Consolidated Financial Statements (concluded)

QUARTERLY RESULTS (UNAUDITED)

Quarterly results fluctuate due mainly to the seasonal nature of the gas
distribution business.  Nicor Gas' restructured rates, effective April 1996,
result in the shifting of some revenues from cold-weather quarters to warm-
weather quarters.
                                                   1997 Quarter Ended
(Millions)                                Mar. 31     June 30     Sept. 30     Dec. 31

Operating revenues                        $ 819.9     $ 244.0      $ 151.1     $ 515.5
Operating income                             47.4        33.7         26.0        41.5
Net income                                   34.7        24.2         15.6        32.4


                                                   1996 Quarter Ended
                                          Mar. 31     June 30     Sept. 30     Dec. 31

Operating revenues                        $ 652.5     $ 284.7      $ 161.0     $ 512.0
Operating income                             51.7        33.9         24.1        42.7
Net income                                   41.0        22.6         12.8        30.7

Nicor Gas Company Page 26

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

None.

PART IV

Item 14. Exhibits, Financial Statement Schedules, and Reports on Form 8-K

(a) 1) Financial Statements:

See Item 8, Financial Statements and Supplementary Data, on page 12 filed herewith, for a list of financial statements.

2) Financial Statement Schedules:

Schedule
 Number                                                        Page

            Report of Independent Public Accountants            13
   II       Valuation and Qualifying Accounts                   27

Schedules other than those listed are omitted because they are not applicable.

3) Exhibits Filed:

See Exhibit Index on pages 30 through 32 filed herewith.

(b) The company did not file a report on Form 8-K during the fourth quarter of 1997.

Nicor Gas Company                                                                     Page 27

Schedule II

VALUATION AND QUALIFYING ACCOUNTS
(Millions)


         Column A                   Column B             Column C                 Column D         Column E
                                                         Additions
                                   Balance at     Charged to      Charged                         Balance at
                                    beginning      costs and      to other                          end of
        Description                 of period      expenses       accounts     Deductions(a)        period

1997

  Allowance
     for uncollectible
     accounts receivable            $    6.1       $   15.3       $      -        $   13.8         $    7.6


1996

  Allowance
     for uncollectible
     accounts receivable            $    4.7       $   11.0       $      -        $    9.6         $    6.1


1995

  Allowance
     for uncollectible
     accounts receivable            $    4.4       $    7.3       $      -        $    7.0         $    4.7



<F1>
(a) Accounts receivable written off, net of recoveries.

Nicor Gas Company Page 28

Signatures

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Nicor Gas Company

Date    March 26, 1998              By       DAVID L. CYRANOSKI
                                             David L. Cyranoski
                                           Senior Vice President,
                                          Secretary and Controller

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities indicated on March 26, 1998.

       Signature                                    Title

    THOMAS L. FISHER                     Chairman, President, Chief
    Thomas L. Fisher                   Executive Officer and Director

   DAVID L. CYRANOSKI                       Senior Vice President,
   David L. Cyranoski                    Secretary and Controller and
                                         Principal Financial Officer

ROBERT M. BEAVERS, JR.*                          Director

BRUCE P. BICKNER*                                Director

JOHN H. BIRDSALL, III*                           Director

W. H. CLARK*                                     Director

DENNIS J. KELLER*                                Director

CHARLES S. LOCKE*                                Director

SIDNEY R. PETERSEN*                              Director

DANIEL R. TOLL*                                  Director

PATRICIA A. WIER*                                Director

*By GEORGE M. BEHRENS
George M. Behrens (Attorney-in-fact)

Nicor Gas Company Page 29

Supplemental Information

Supplemental Information to be Furnished With Reports Filed Pursuant to
Section 15(d) of the Act by Registrants Which Have Not Registered Securities Pursuant to Section 12 of the Act:

No annual report or proxy material has been sent to security holders as Nicor Gas is a wholly owned subsidiary of Nicor Inc.

Nicor Gas Company                                                    Page 30

Exhibit Index

Exhibit
 Number                           Description of Document

  1.01       Underwriting agreement, dated February 18, 1998, between the
             company and Salomon Brothers Inc.

  3.01    *  Articles of Incorporation of the company.  (File No. 1-7296,
             Form 10-K for 1980, Exhibit 3-01.)

  3.02    *  Amendment to Articles of Incorporation of the company.  (File
             No. 1-7296, Form 10-Q for June 1994, Exhibit 3.01.)

  3.03    *  By-Laws of the company as amended by the company's Board of
             Directors on May 3, 1995.  (File No. 1-7296, Form 10-Q for March
             1995, Exhibit 3(ii).01.)

  4.01    *  Indenture of Commonwealth Edison Company to Continental Illinois
             National Bank and Trust Company of Chicago, Trustee, dated as of
             January 1, 1954.  (File No. 1-7296, Form 10-K for 1995,
             Exhibit 4.01.)

  4.02    *  Indenture of Adoption of the company to Continental Illinois
             National Bank and Trust Company of Chicago, Trustee, dated
             February 9, 1954.  (File No. 1-7296, Form 10-K for 1995,
             Exhibit 4.02.)

  4.03    *  Supplemental Indenture, dated June 1, 1963, of the company to
             Continental Illinois National Bank and Trust Company of Chicago,
             Trustee, under Indenture dated as of January 1, 1954.  (File
             No. 2-21490, Form S-9, Exhibit 2-8.)

  4.04    *  Supplemental Indenture, dated May 1, 1966, of the company to
             Continental Illinois National Bank and Trust Company of Chicago,
             Trustee, under Indenture dated as of January 1, 1954.  (File
             No. 2-25292, Form S-9, Exhibit 2-4.)

  4.05    *  Supplemental Indenture, dated June 1, 1971, of the company to
             Continental Illinois National Bank and Trust Company of Chicago,
             Trustee, under Indenture dated as of January 1, 1954.  (File
             No. 2-44647, Form S-7, Exhibit 2-03.)

  4.06    *  Supplemental Indenture, dated April 30, 1976, between Nicor Inc.
             and Continental Illinois National Bank and Trust Company of
             Chicago, Trustee, under Indenture dated as of January 1, 1954.
             (File No. 2-56578, Form S-9, Exhibit 2-25.)

  4.07    *  Supplemental Indenture, dated April 30, 1976, of the company to
             Continental Illinois National Bank and Trust Company of Chicago,
             Trustee, under Indenture dated as of January 1, 1954.  (File
             No. 2-56578, Form S-9, Exhibit 2-21.)




Nicor Gas Company                                                    Page 31

Exhibit Index (continued)

Exhibit
 Number                           Description of Document

  4.08    *  Supplemental Indenture, dated August 15, 1991, of the company to
             Continental Bank, National Association, Trustee, under Indenture
             dated as of January 1, 1954.  (File No. 1-7296, Form 8-K for
             August 1991, Exhibit 4-01.)

  4.09    *  Supplemental Indenture, dated July 15, 1992, of the company to
             Continental Bank, National Association, Trustee, under Indenture
             dated as of January 1, 1954.  (File No. 1-7296, Form 10-Q for
             June 1992, Exhibit 4-01.)

  4.10    *  Supplemental Indenture, dated February 1, 1993, of the company to
             Continental Bank, National Association, Trustee, under Indenture
             dated as of January 1, 1954.  (File No. 1-7296, Form 10-K for
             1992, Exhibit 4-17.)

  4.11    *  Supplemental Indenture, dated May 1, 1993, of the company to
             Continental Bank, National Association, Trustee, under Indenture
             dated as of January 1, 1954.  (File No. 1-7296, Form 10-Q for
             March 1993, Exhibit 4-02.)

  4.12    *  Supplemental Indenture, dated July 1, 1993, of the company to
             Continental Bank, National Association, Trustee, under Indenture
             dated as of January 1, 1954.  (File No. 1-7296, Form 10-Q for
             June 1993, Exhibit 4-01.)

  4.13    *  Supplemental Indenture, dated August 15, 1994, of the company to
             Continental Bank, Trustee, under Indenture dated as of January 1,
             1954.  (File No. 1-7296, Form 10-Q for September 1994,
             Exhibit 4.01.)

  4.14    *  Supplemental Indenture, dated October 15, 1995, of the company to
             Bank of America Illinois, Trustee, under Indenture dated as of
             January 1, 1954.  (File No. 1-7296, Form 10-Q for September 1995,
             Exhibit 4.01.)

  4.15    *  Supplemental Indenture, dated May 10, 1996, of the company to
             Harris Trust and Savings Bank, Trustee, under Indenture dated as
             of January 1, 1954.  (File No. 1-7296, Form 10-Q for June 1996,
             Exhibit 4.01.)

  4.16    *  Supplemental Indenture, dated August 1, 1996, of the company to
             Harris Trust and Savings Bank, Trustee, under Indenture dated as
             of January 1, 1954.  (File No. 1-7296, Form 10-Q for June 1996,
             Exhibit 4.02.)

  4.17    *  Supplemental Indenture, dated June 1, 1997, of the company to
             Harris Trust and Savings Bank, Trustee, under Indenture dated as
             of January 1, 1954.  (File No. 1-7296, Form 10-Q for June 1997,
             Exhibit 4.01.)




Nicor Gas Company                                                    Page 32

Exhibit Index (concluded)

Exhibit
 Number                           Description of Document

  4.18    *  Supplemental Indenture, dated October 15, 1997, of the company to
             Harris Trust and Savings Bank, Trustee, under Indenture dated as
             of January 1, 1954.  (File No. 1-7296, Form 10-Q for September
             1997, Exhibit 4.01.)

  4.19       Supplemental Indenture, dated February 15, 1998, of the company
             to Harris Trust and Savings Bank, Trustee, under Indenture dated
             as of January 1, 1954.

 12.01       Computation of Consolidated Ratio of Earnings to Fixed Charges.

 23.01       Consent of Independent Public Accountants.

 24.01       Powers of Attorney.

 27.01       Financial Data Schedule.

* These exhibits have been previously filed with the Securities and Exchange Commission as exhibits to registration statements or to other filings with the Commission and are incorporated herein as exhibits by reference. The file number and exhibit number of each such exhibit, where applicable, are stated in parentheses in the description of such exhibit.

Upon written request, the company will furnish free of charge a copy of any exhibit. Requests should be sent to Investor Relations at the corporate headquarters.


Nicor Gas Company Form 10-K Exhibit 1.01

NORTHERN ILLINOIS GAS COMPANY

$50,000,000

FIRST MORTGAGE BONDS

6.58% SERIES DUE FEBRUARY 15, 2028

UNDERWRITING AGREEMENT

Salomon Brothers Inc
7 World Trade Center
New York, New York 10048

February 18, 1998

Dear Sirs:

Northern Illinois Gas Company, doing business as Nicor Gas Company ("Nicor Gas" or the "Company") proposes, subject to the terms and conditions stated herein and in the General Terms and Conditions of Underwriting Agreement in the form of Annex A hereto, a copy of which you have previously received, to issue and sell to the Underwriter named above (the "Underwriter"), $50,000,000 aggregate principal amount of the Company's First Mortgage Bonds (the "Bonds"). All of the provisions of such General Terms and Conditions of Underwriting Agreement are incorporated herein by reference in their entirety, and shall be deemed to be a part of this Underwriting Agreement to the same extent as if such provisions had been set forth in full herein. Unless otherwise defined herein, terms defined in the General Terms and Conditions of Underwriting Agreement are used herein as therein defined.

An amendment to the Registration Statement, or a supplement to the Prospectus, as the case may be, relating to the Bonds in the form heretofore delivered to you is now proposed to be filed or mailed for filing with the Commission. Such amendment or supplement sets forth the terms of the Bonds.

Subject to the terms and conditions set forth herein, the Company agrees to issue and sell to the Underwriter, and the Underwriter agrees to purchase from the Company, all of the Bonds on the following terms and conditions:

Aggregate principal amount of Bonds to be        $50,000,000
  purchased:.................................
Rate of interest per annum to be borne by the    6.58% (such rate to be a multiple of .001%)
  Bonds (payable semiannually):..............
Maturity date of the Bonds:..................    February 15, 2028
Price to be paid to the Company for the          99.093% of the principal amount of the Bonds
  Bonds:.....................................    (not less than 99%) plus accrued interest from
                                                 date of Supplemental Indenture to the date of
                                                 delivery of the Bonds.
Initial public offering price of the             99.968% of the principal amount of the Bonds
  Bonds:.....................................    plus accrued interest from date of Supplemental
                                                 Indenture to the date of delivery of the Bonds.
                                                 (If other, give details.)
Place for delivery of Bonds:.................    The Depository Trust Company
                                                 55 Water Street
                                                 New York, New York 10004
Date and time of Time of Delivery:...........    February 25, 1998 at 9:00 a.m. Chicago time
Place for checking Bonds on the business day     The Depository Trust Company
  prior to Time of Delivery:.................    55 Water Street
                                                 New York, New York 10004

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Redemption and Sinking Fund:.................    The Bonds may not be called for redemption by
                                                 the Company. No sinking fund will be provided.
Address for notices per Section 12 of the
  General Terms and Conditions of
  Underwriting Agreement:....................    Salomon Brothers Inc
                                                 7 World Trade Center
                                                 New York, New York 10048

If the foregoing is in accordance with your understanding, please sign and return to us the enclosed counterparts hereof, whereupon it will become a binding agreement between the Underwriter and the Company in accordance with its terms.

Very truly yours,

NORTHERN ILLINOIS GAS COMPANY

By

Title:

The foregoing Underwriting Agreement is hereby confirmed and accepted as of the
date first above written.

SALOMON BROTHERS INC

By
Title:

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ANNEX A

NORTHERN ILLINOIS GAS COMPANY

$50,000,000

FIRST MORTGAGE BONDS

GENERAL TERMS AND CONDITIONS OF UNDERWRITING AGREEMENT

Northern Illinois Gas Company, an Illinois corporation (the "Company"), proposes to enter into an Underwriting Agreement into which these General Terms and Conditions are incorporated by reference (the "Underwriting Agreement") and, subject to the terms and conditions stated therein, to issue and sell to the underwriter or underwriters named in Schedule I to the Underwriting Agreement up to $50,000,000 aggregate principal amount of its First Mortgage Bonds (hereinafter called the "Bonds") under the registration statement referred to in
Section 2(a) hereof. Such Bonds will be issued under the Company's Indenture dated as of January 1, 1954, to Continental Bank, National Association, Trustee (the "Trustee"), as supplemented by supplemental indentures dated February 9, 1954, April 1, 1956, June 1, 1959, July 1, 1960, June 1, 1963, July 1, 1963, August 1, 1964, August 1, 1965, May 1, 1966, August 1, 1966, July 1, 1967, June 1, 1968, December 1, 1969, August 1, 1970, June 1, 1971, July 1, 1972, July 1, 1973, April 1, 1975, April 30, 1976, April 30, 1976, July 1, 1976, August 1, 1976, December 1, 1977, January 15, 1979, December 1, 1981, March 1, 1983, October 1, 1984, December 1, 1986, March 15, 1988, July 1, 1988, July 1, 1989, July 15, 1990, August 15, 1991, July 15, 1992, February 1, 1993, March 15, 1993, May 1, 1993, July 1, 1993, August 15, 1994, October 15, 1995, May 10, 1996, August 1, 1996, June 1, 1997 and October 15, 1997 respectively, and as to be further supplemented by a Supplemental Indenture (the "Supplemental Indenture") which will be dated the first or fifteenth day of the calendar month in which the "Time of Delivery" (as hereinafter defined) falls, creating the series in which the Bonds are to be issued. Said Indenture as so supplemented is hereinafter called the "Indenture." The term "Underwriters" herein shall refer to the several persons, firms and corporations named in Schedule I to the Underwriting Agreement and the term "Representatives" herein shall refer to the Underwriters identified as the Representatives who are acting on behalf of the Underwriters (including themselves) in the Underwriting Agreement. All obligations of the Underwriters under the Underwriting Agreement are several and not joint. The terms "Underwriters", "Representatives", "persons", "firms" and "corporations" shall include the singular as well as the plural.

The terms of the issuance of the Bonds shall be as specified in the Underwriting Agreement. The Underwriting Agreement shall constitute an agreement by the Company and the Underwriters to be bound by all of the provisions of these General Terms and Conditions of Underwriting Agreement, as follows:

SECTION 1. Sale of Bonds. Sales of the Bonds will be made to the Underwriters, for whom the Representatives will act as such. The obligation of the Company to issue and sell any of the Bonds and the obligation of any of the Underwriters to purchase any of the Bonds shall be evidenced by the Underwriting Agreement. The Underwriting Agreement shall specify the aggregate principal amount of Bonds to be purchased, the rate and time of payment of interest to be borne by the Bonds, the maturity date of the Bonds, the price to be paid to the Company for the Bonds, the initial public offering price or other offering terms of such Bonds and the redemption prices and other special terms, if any, relating to the Bonds, the names of the Underwriters of such Bonds, the names of the Representatives of such Underwriters and the amount of Bonds to be purchased by each Underwriter, and, subject to the provisions of Section 3 hereof, shall set forth the date, time and manner of the delivery of such Bonds. The terms of the Bonds will be set forth in the Prospectus Supplement (as hereinafter defined). The Underwriting Agreement shall be in the form of an executed writing (which may be in counterparts) and may be evidenced by an exchange of telecopied communications or any other rapid transmission device to produce a written record of communications transmitted.

SECTION 2. Representations and Warranties of the Company. The Company represents and warrants to, and agrees with, the several Underwriters that:

(a) A registration statement on Form S-3 with respect to the Bonds, including a related preliminary prospectus, has been prepared by the Company in conformity with the requirements of the Securities Act of 1993, as amended (the "Act"), and the rules and regulations of the Securities and Exchange Commission (the "Commission") under the Act (the "Regulations"), and has been filed with the Commission on December 18, 1997 and, if one or more amendments to such registration statement, which may include an amended preliminary prospectus, have been filed with the Commission, such amendments have been similarly prepared; and such registration statement has become effective. Such registration statement, as amended to the date of the Underwriting Agreement, together with the prospectus supplement referred to below is hereinafter referred to as the "Registration Statement". Such prospectus as supplemented specifically relating to the Bonds and filed with the Commission under Rule 424(b) of the Act is hereinafter referred to as the "Prospectus". The Prospectus has been prepared by the Company in conformity with the requirements of the Act and the Regulations. Copies of the Registration Statement and any related prospectus have been delivered to the Representatives. As used herein, Registration Statement, Prospectus and preliminary prospectus shall include, in each case, the material incorporated therein pursuant to Item 12 of Form S-3 filed under the Securities Exchange Act of 1934 (the "1934 Act") on or prior to the date of the Underwriting Agreement, and "amended", "amendment" or "supplement" with respect to the Registration Statement or the Prospectus shall be deemed to include the filing by the Company of any document pursuant to Sections 13(a), 13(c), 14 or 15(d) of the 1934 Act after the date of the Underwriting Agreement.

(b) The registration statement at the time it became effective, and the related prospectus and any amendments and supplements thereto filed prior to the date of the Underwriting Agreement, conformed in all material respects to the provisions of the Act and the Trust Indenture Act of 1939, as amended (the "Trust Indenture Act") and the rules and regulations of the Commission thereunder, on the date of the Underwriting Agreement and at the Time of Delivery (referred to in Section 3) the Registration Statement, the Prospectus, and any amendments and supplements thereto, and the Indenture, will conform in all material respects to the Act, the Trust Indenture Act and the respective rules and regulations of the Commission thereunder; and at the time the registration statement became effective, the registration statement and related prospectus did not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; and at the date of this Underwriting Agreement and at the Time of Delivery, the Registration Statement and the Prospectus and any amendments and supplements thereto do not and will not contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein not misleading; provided, however, that none of the representations and warranties in this subsection shall apply to statements in or omissions from the Registration Statement or Prospectus or any amendment or supplement thereto made in reliance upon and in conformity with information respecting the Underwriters furnished to the Company in writing by or on behalf of any Underwriter through the Representatives expressly for use in the Registration Statement or Prospectus.

(c) The documents incorporated by reference into the Prospectus, at the time they were filed with the Commission, complied in all material respects with the requirements of the 1934 Act and the rules and regulations of the Commission thereunder (the "1934 Regulations"), and, at the date of this Underwriting Agreement and at the Time of Delivery, when read together with the Prospectus and any supplement thereto will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, and any documents filed after the date of the Underwriting Agreement and so incorporated by reference in the Prospectus will, when they are filed with the Commission, comply in all material respects with the requirements of the 1934 Act and the 1934 Regulations, and when read together with the Prospectus and any supplement thereto will not contain an untrue statement of material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading.

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(d) Arthur Andersen LLP are independent public accountants with respect to the Company and its subsidiaries as required by the Act and the Regulations.

(e) The financial statements included in the Registration Statement present fairly the financial position of the Company and its consolidated subsidiaries as of the dates indicated and the results of their operations for the periods specified, and said financial statements have been prepared in conformity with generally accepted accounting principles applied on a consistent basis during the periods involved.

(f) The Company is a corporation in good standing, duly organized and validly existing under the laws of Illinois, and has due corporate authority to carry on the business in which it is engaged and to own and operate the properties used by it in such business as described in the Prospectus. The Company's subsidiary constitutes less than 5% of its consolidated assets and during the year ended December 31, 1997 contributed less than 5% of its consolidated annual operating revenues and net income, and the Company does not consider its subsidiary to be material.

(g) The execution and delivery of the Underwriting Agreement have been duly authorized by the Company and the Underwriting Agreement constitutes a valid and legally binding obligation of the Company; the Bonds have been duly authorized, and when issued and delivered pursuant to the Underwriting Agreement and the Indenture, will have been duly executed, authenticated, issued and delivered and will constitute valid and legally binding obligations of the Company in accordance with their respective terms, entitled to the benefits provided by the Indenture; the Supplemental Indenture has been duly authorized in substantially the form filed as an exhibit to the Registration Statement and, when executed and delivered by the Company and the Trustee, will constitute a valid and legally binding instrument enforceable in accordance with its terms, except to the extent the enforceability of the Bonds and the Indenture may be limited by bankruptcy, insolvency, reorganization or other laws of general application relating to or affecting the enforcement of creditors' rights or general equity principles; and the Indenture and the Bonds as executed and delivered will conform in all material respects to the descriptions thereof in the Prospectus.

(h) The issue and sale of the Bonds and the compliance by the Company with all of the provisions of the Bonds, the Indenture, and the Underwriting Agreement and the transactions contemplated thereby will not conflict with or result in any breach or violation of any of the provisions of, or constitute (disregarding any grace or notice period) a default under, or result in the imposition of any lien, charge or encumbrance upon any property or assets of the Company pursuant to the terms of, any other indenture, or any mortgage, loan agreement, contract, note, lease or other agreement or instrument to which the Company is a party or by which the Company may be bound or to which any of the property or assets of the Company is subject, nor will such action result in any violation of the provisions of the charter or by-laws of the Company or any statute or any order, rule or regulation applicable to the Company of any court or any federal, state or other regulatory authority or other governmental body having jurisdiction over the Company or any of its properties.

(i) Since the respective dates as of which information is given in the Registration Statement and Prospectus and except as may otherwise be stated or contemplated therein; (i) there has not been any material adverse change in the condition, financial or otherwise, of the Company and its subsidiaries considered as one enterprise, or in the earnings, affairs, business prospects or properties of the Company and its subsidiaries considered as one enterprise, whether or not arising in the ordinary course of business or arising from any court or governmental action, order or decree, and (ii) there has been no transaction entered into by the Company or any subsidiary which is material to the Company and its subsidiaries considered as one enterprise, other than transactions in the ordinary course of business.

(j) Except as set forth in the Prospectus, the Company, with minor exceptions, and subject to noncompliance with certain procedural and other requirements in the procurement and granting of gas franchises in a number of smaller municipalities formerly served by Mid-Illinois Gas Company, has statutory authority, franchises, licenses, rights-of-way, easements and consents, free from unduly burdensome restrictions and adequate for the conduct of the business in which it is engaged.

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(k) The Illinois Commerce Commission has entered an order authorizing the issue and sale of the Bonds by the Company upon terms consistent with the Underwriting Agreement, and no other consent, approval, authorization or other order or filing with any regulatory or governmental body is required for the issuance and sale of the Bonds and consummation of the transactions contemplated hereby, except such consents, approvals, authorizations, registrations or qualifications as may be required under state securities or Blue Sky laws in connection with the purchase and distribution of the Bonds by the Underwriters.

(l) The Company is not in violation of its charter or, except as disclosed in the Prospectus, in default in the performance or observance of any obligation, agreement, covenant or condition contained in any contract, indenture, mortgage, loan agreement, note, lease or other instrument to which it is a party or by which it or its property is bound or affected which is material to the Company and its subsidiary considered as one enterprise.

(m) Except as set forth in the Registration Statement and Prospectus, there are no legal or governmental proceedings pending to which the Company or its subsidiary is a party or of which any property of the Company or its subsidiary is the subject, and, to the best of the Company's knowledge, no such proceedings are threatened or contemplated by governmental authorities or threatened by others, other than proceedings which, if determined adversely to the Company and its subsidiary, would not individually or in the aggregate have a material adverse effect on the business, properties, financial position, net worth or results of operations of the Company and its subsidiary considered as a whole.

(n) the Company has good and sufficient title to all property described or referred to in the Indenture and purported to be conveyed thereby (except property released from the lien of the Indenture in connection with the sale or other disposition thereof), subject only to the lien of the Indenture and to permitted liens as defined therein; the Indenture has been duly filed for recordation in such manner and in such places as is required by law in order to give constructive notice of, establish, preserve and protect the lien of the Indenture; the Indenture constitutes a valid, direct first mortgage lien, subject only to permitted liens, on substantially all property of the Company, except property expressly excepted by the terms of the Indenture; the Indenture will, when recorded or registered by the Company in accordance with its covenants under the Indenture, constitute a valid, direct first mortgage lien on all property of the character of that now subject to the lien of the Indenture hereafter acquired by the Company, subject only to permitted liens and to liens, if any, existing or placed on such after-acquired property at the time of the acquisition thereof;

Any certificate signed by any officer of the Company and delivered to you or to Underwriters' counsel shall be deemed a representation and warranty by the Company to each Underwriter as to the statements made therein.

SECTION 3. Purchase, Sale and Delivery of Bonds. Following the execution of the Underwriting Agreement, the several Underwriters propose to make a public offering of their respective portions of the Bonds as soon as in the Representatives' judgment it is advisable upon the terms and conditions set forth in the Prospectus Supplement.

The Bonds to be purchased by each Underwriter pursuant to the Underwriting Agreement, in definitive form and registered in such names as the Representatives may request upon at least forty-eight hours' prior notice to the Company, shall be delivered by or on behalf of the Company to the Representatives for the respective accounts of the several Underwriters, against payment therefor as specified in the Underwriting Agreement in immediately available funds, at the office of Mayer, Brown & Platt, 190 South LaSalle Street, Chicago, Illinois 60603 (except as hereinafter provided with respect to delivery of such Bonds), at the time and date specified in the Underwriting Agreement or at such other place and time and date as the Representatives and the Company may agree upon in writing, such time and date being herein called the "Time of Delivery". If specified by the Representatives in the Underwriting Agreement, delivery of the Bonds will be made at the Time of Delivery at such place in New York, New York as shall have been so specified against payment therefor in Chicago as aforesaid.

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SECTION 4. Covenants of the Company. The Company covenants with each Underwriter that:

(a) The Company will notify the Representatives immediately and confirm the notice in writing (i) of the receipt of any request by the Commission for any amendment or supplement to the Registration Statement or the Prospectus or any amendment or supplement thereto or for additional information, and (ii) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or of the initiation or threatened initiation of any proceedings for that purpose or of the suspension or threatened suspension of the qualification of the Bonds for offering or sale in any jurisdiction. The Company will make every reasonable effort to prevent the issuance by the Commission of any stop order and, if any such stop order shall at any time be issued, to obtain the lifting thereof at the earliest moment.

(b) The Company will not file any amendment to the Registration Statement or any amendment or supplement to the Prospectus (including a prospectus filed pursuant to Rule 424 and including documents deemed to be incorporated by reference into the Prospectus) without first having furnished the Representatives with a copy of the proposed form thereof and given the Representatives a reasonable opportunity to review and comment respecting the same and having given reasonable consideration to any comments or objections made by the Representatives.

(c) The Company will deliver to each of the Representatives, as soon as available, one signed copy of the Registration Statement as originally filed and of each amendment thereto, including, in each case, documents incorporated by reference into the Registration Statement and one set of exhibits thereto (other than exhibits incorporated by reference which will be furnished upon specific request), and will also deliver to the Representatives a reasonable number of conformed copies of the Registration Statement as originally filed and of each amendment and post-effective amendment thereto including such incorporated documents (without exhibits) for each of the Underwriters.

(d) The Company will deliver to each Underwriter from time to time during the period when a prospectus is required to be delivered under the Act such number of copies of the Prospectus (as amended or supplemented and including incorporated documents) as the Representatives may reasonably request for the purposes contemplated by the Act or the Regulations; provided, however, that the delivery of copies of the Prospectus (as amended or supplemented and including incorporated documents) more than nine months after the date of the Underwriting Agreement shall be at the expense of the Underwriter requesting such delivery.

(e) During the period when a prospectus is required to be delivered under the Act, the Company will comply so far as it is able, and at its own expense (for a period not to exceed nine months), with all requirements imposed upon it by the Act, and by Sections 13 and 14 of the 1934 Act, as now or hereafter amended, and by the Regulations, as from time to time in force, so far as necessary to permit the continuance of sales of or dealing in the Bonds during such period in accordance with the provisions hereof and of the Prospectus.

(f) If any event shall occur as a result of which it is necessary, in the opinion of counsel for the Company and of Underwriters' counsel, to amend or supplement the Prospectus in order to make the Prospectus not misleading in the light of the circumstances existing at the time it is delivered to a purchaser, or if it is necessary to amend or supplement the Prospectus to comply with law, the Company will forthwith prepare and furnish to the Underwriters, without expense to them except as otherwise provided in subsection (d) of this Section 4, a reasonable number of copies of an amendment or amendments or a supplement or supplements to the Prospectus (in the form referred to in subsection (b) of this Section 4) which will amend or supplement the Prospectus so that as amended or supplemented it will not contain any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein not misleading, or so that the Prospectus will comply with law. For the purposes of this subsection, the Company will furnish such information as the Representatives may from time to time reasonably request.

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(g) The Company will endeavor in good faith, in cooperation with the Underwriters, to qualify the Bonds for offering and sale under the applicable securities laws of such jurisdictions as the Representatives may designate; provided, however, that the Company shall not be obligated to file any general consent to service or to qualify as a foreign corporation or as a dealer in securities in any jurisdiction in which it is not so qualified. In each jurisdiction where any of the Bonds shall be qualified as above provided, the Company will make and file such statements and reports in each year as are or may be reasonably required by the laws thereof.

(h) The Company will make generally available to its security holders as soon as practicable, but not later than 75 days after the close of the period covered thereby, an earnings statement (in form complying with the provisions of Section 11(a) of the Act and the Regulations thereunder (including, at the option of the Company, Rule 158), which need not be certified by independent public accountants unless required by the Act or the Regulations), covering a twelve-month period beginning on the first day of the calendar quarter following the Time of Delivery.

(i) The Company agrees that it will not publicly offer or sell any intermediate or long-term debt between the date of the Underwriting Agreement and Time of Delivery without the prior written consent of the Representatives.

SECTION 5. Payment of Expenses. The Company will pay all expenses incident to the performance of its obligations under the Underwriting Agreement, including (i) the printing and filing by the Company of the registration statement and the printing of the Underwriting Agreement, any Agreement Among Underwriters, any Selling Agreement, the Supplemental Indenture and the Underwriters' Questionnaire, (ii) the authorization, issuance and delivery of the Bonds to the Underwriters, including the printing and engraving of the Bonds, and all taxes, if any, upon the issuance and sale of the Bonds to the Underwriters, (iii) the qualification of the Bonds under the securities laws of the various jurisdictions in accordance with the provisions of subsection (g) of
Section 4, including filing fees and fees and disbursements of Underwriters' counsel in connection with such qualification and in connection with the preparation of the Blue Sky Survey (such fees of Underwriters' counsel not to exceed $5,000 in the aggregate), (iv) any fees charged by securities rating services for rating the Bonds, (v) the fees and expenses of the Trustee and its counsel in connection with the Bonds and the Supplemental Indenture, (vi) the printing and delivery to the Underwriters and dealers in quantities as hereinbefore stated of copies of the registration statement and all amendments thereto, of any preliminary prospectuses and amended preliminary prospectuses, of the Registration Statement and any amendments thereto, and of the Prospectus and any amendments or supplements thereto, and (vii) the cost of printing and delivery to the Underwriters of copies of the Blue Sky Survey.

If this Agreement is terminated by the Representatives in accordance with the provisions of Section 6 or Section 10(b), or is prevented by the Company from becoming effective in accordance with the provisions of Section 10(a), the Company shall reimburse the Underwriters severally for their out-of-pocket expenses, including the reasonable fees and disbursements of counsel for the Underwriters incurred in connection with the offering.

SECTION 6. Conditions of Underwriters' Obligations. The several obligations of the Underwriters hereunder are subject to the accuracy of and compliance with the representations and warranties of the Company herein contained, to the performance by the Company of its obligations hereunder and to the following further conditions:

(a) At the Time of Delivery no stop order suspending the effectiveness of the Registration Statement shall have been issued under the Act or proceedings therefor initiated or threatened by the Commission.

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(b) At the Time of Delivery the Representatives shall have received:

(1) The favorable opinion, dated as of the Time of Delivery, of Mayer, Brown & Platt, counsel for the Company, in form and substance satisfactory to counsel for the Underwriters, to the effect that:

(i) the Company is a corporation in good standing, duly organized and validly existing under the laws of the State of Illinois and has due corporate authority to carry on the business in which it is engaged and to own and operate the properties used by it in such business;

(ii) the Indenture is in due and proper form, has been duly and validly authorized by the necessary corporate action and by orders duly entered by the Illinois Commerce Commission; no authorization, approval, consent, certificate or order of any other state commission or regulatory authority or of any federal commission or regulatory authority not already obtained is required in respect of the execution and delivery of the Indenture; and the Indenture has been duly and validly executed and delivered and is a valid and enforceable instrument in accordance with its terms, except as enforcement of provisions of the Indenture may be limited by bankruptcy or other laws of general application affecting the enforcement of creditors' rights and by general equity principles;

(iii) the Bonds are in due and proper form; the issue and sale of the Bonds by the Company in accordance with the terms of the Underwriting Agreement have been duly and validly authorized by the necessary corporate action and by order duly entered by the Illinois Commerce Commission; no authorization, approval, consent, certificate or order of any other state commission or regulatory authority or of any federal commission or regulatory authority not already obtained is required in respect of such issue and sale (except such consents, approvals, authorizations, registrations or qualifications as may be required under state securities or Blue Sky laws in connection with the purchase and distribution of the Bonds by the Underwriters); the Bonds have been duly executed and delivered to the Underwriters against payment of the agreed consideration therefor and, assuming due authentication thereof by the Trustee, constitute valid and enforceable obligations of the Company in accordance with their terms, secured by the lien of and, with like exception as noted in the foregoing subdivision (ii), entitled to the benefits provided by the Indenture, and the registered owners of the Bonds will be entitled to the payment of principal and interest, and premium in case of redemption, as therein provided; the Bonds and the Indenture conform as to legal matters in all material respects with the statements concerning them made in the Prospectus, and such statements accurately set forth the matters respecting the Bonds and the Indenture required to be set forth in the Prospectus;

(iv) The Registration Statement is effective under the Act and the Indenture has been duly qualified under the Trust Indenture Act, and to the best of the knowledge of said counsel no proceedings for a stop order are pending or threatened under Section 8(d) of the Act;

(v) the execution and delivery of the Underwriting Agreement by the Company has been duly authorized by the necessary corporate action, and the Underwriting Agreement has been duly executed and delivered by the Company;

(vi) the Company has good and sufficient title to all property described or referred to in the Indenture and purported to be conveyed thereby (except property released from the lien of the Indenture in connection with the sale or other disposition thereof), subject only to the lien of the Indenture and to permitted liens as defined therein; the Indenture has been duly filed for recordation in such manner and in such places as is required by law in order to give constructive notice of, establish, preserve and protect the lien of the Indenture; the Indenture constitutes a valid, direct first mortgage lien, subject only to permitted liens, on substantially all property of the Company, except property expressly excepted by the terms of the Indenture; the Indenture will, when recorded or registered by the Company in accordance with its covenants under the

7

Indenture, constitute a valid, direct first mortgage lien on all property of the character of that now subject to the lien of the Indenture hereafter acquired by the Company, subject only to permitted liens and to liens, if any, existing or placed on such after-acquired property at the time of the acquisition thereof;

(vii) the issue and sale of the Bonds and the compliance by the Company with all of the provisions of the Bonds, the Indenture and the Underwriting Agreement will not conflict with or result in a breach or violation of any of the provisions of, or constitute (disregarding any grace or notice period) a default under, any indenture, mortgage, loan agreement, contract, note, lease or other agreement or instrument, known to such counsel, to which the Company is a party or by which the Company is bound or to which any of the property or assets of the Company is subject (with such exceptions as are in the aggregate not material to the business or financial condition of the Company or the validity of the Bonds), nor will such action result in any violation of the provisions of the Charter or By-Laws of the Company, or, to the best of their knowledge, any statute or any order, rule or regulation applicable to the Company of any court or governmental agency or body having jurisdiction over the Company or any of its properties (except such consents, approvals, authorizations, registrations or qualifications as may be required under state securities or Blue Sky laws in connection with the purchase and distribution of the Bonds by the Underwriters);

(viii) at the time the registration statement became effective, the registration statement and the related prospectus (other than the financial statements and notices thereto and supporting schedules and other financial information included therein, as to which no opinion need be rendered) complied as to form in all material respects with the requirements of the Act and the Trust Indenture Act and the Regulations;

(ix) with minor exceptions, and subject to noncompliance with certain procedural and other requirements in the procurement and granting of gas franchises in a number of smaller municipalities formerly served by Mid-Illinois Gas Company, the Company holds franchises from all of the incorporated cities and villages included in the communities in which the Company renders gas service; all of the franchises so held by the Company are valid and subsisting and authorize it to engage in the business conducted by it in the respective municipalities granting such franchises; the Company also holds certificates of public convenience and necessity issued by the Illinois Commerce Commission, which are valid and subsisting and constitute due authorization by such commission for the conduct by the Company of its operations in all areas served;

(x) to the best of their knowledge and information, there are no contracts, indentures, mortgages, loan agreements, notes, leases or other instruments of a character required to be described in the Registration Statement or Prospectus or to be filed as exhibits to the Registration Statement other than those described therein or filed or incorporated by reference as exhibits thereto and the descriptions thereof or reference thereto are correct; and

(xi) except as disclosed in the Prospectus, there are no material pending or threatened legal proceedings, considering the Company and the subsidiaries as a single enterprise, known to said counsel, to which the Company or any subsidiary is a party or of which property of the Company or any subsidiary is the subject, and to the best of the knowledge of said counsel there are no such proceedings contemplated by governmental authorities.

Such counsel shall further state that, based upon their participation in the preparation of the Registration Statement and the Prospectus, and any amendment or supplement thereto, and upon their review and discussions of the contents thereof, but without independent check or verification except as specified, nothing has come to their attention that has caused them to believe that the Registration Statement, at the time it became effective, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading or that the Prospectus, and any amendment or supplement

8

thereto, at the date the Registration Statement became effective, the date of this Agreement or at the Time of Delivery, contained an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading.

(2) The favorable opinion of Wildman, Harrold, Allen & Dixon, counsel for the Underwriters, with respect to the incorporation of the Company, the validity of the Bonds and the Indenture, the Registration Statement, the Prospectus and other related matters as the Representatives may reasonably request; provided that any opinion requested with respect to the jurisdiction of regulatory authorities (other than the Illinois Commerce Commission, the Securities and Exchange Commission and state securities or Blue Sky authorities) and the matters in subdivisions (vi) and (ix) above will rely upon the opinion of Mayer, Brown & Platt.

(c) At the effective date of the Registration Statement and at the Time of Delivery the Representatives shall have received a letter from Arthur Andersen LLP, dated the effective date or Time of Delivery, respectively, in form and substance satisfactory to the Representatives, advising that (i) they are independent public accountants with respect to the Company and its subsidiaries as required by the Act and the 1934 Act and the applicable Regulations, (ii) in their opinion, the audited consolidated financial statements and any supplemental financial information and schedules of the Company examined by them and incorporated by reference in the Registration Statement and Prospectus comply as to form in all material respects with the applicable accounting requirements of the Act, the 1934 Act and the applicable Regulations, (iii) on the basis of a reading of the latest available unaudited interim consolidated financial statements prepared by the Company, a reading of the minutes of meetings of the shareholder and the board of directors and executive committee of the Company and its subsidiaries, consultation with officers of the Company responsible for financial and accounting matters and other specified procedures, nothing has come to their attention which caused them to believe that (A) the unaudited interim condensed consolidated financial statements included or incorporated by reference in the Prospectus do not comply as to form in all material respects with the applicable accounting requirements of the Act, the 1934 Act and the applicable Regulations or are not in conformity with generally accepted accounting principles applied on a basis substantially consistent with that of the audited financial statements incorporated as aforesaid, (B) the unaudited income statement data and balance sheet data (other than such data for the periods referred to in (A) above) included or incorporated by reference in the Prospectus do not agree with the corresponding items in the audited or unaudited, as the case may be, financial statements from which such data were derived or were not determined on a basis substantially consistent with that of the corresponding amounts included in the audited consolidated financial statements of the Company incorporated in the Registration Statement and Prospectus, or (C) at a specified date within five business days of the date of such letter with respect to (1) below, and during the period from the date of the latest audited consolidated financial statements or unaudited interim condensed consolidated financial statements, as the case may be, incorporated in the Prospectus to the date of the latest available unaudited interim consolidated financial statements (if any) prepared by the Company with respect to (2) below, except in all instances as set forth in or contemplated by the Prospectus or as set forth in such letter: (1) there was any increase in the consolidated long-term debt of the Company and its subsidiaries, as compared with the amounts set forth in the latest balance sheet included or incorporated by reference in the Prospectus, or
(2) there were any decreases in consolidated operating income or net income as compared with the corresponding period in the preceding year; and (iv) they have carried out specified procedures performed for the purpose of comparing certain financial information and percentages (which is limited to financial information derived from general accounting records of the Company) specified by the Representatives and appearing in the Registration Statement or in schedules or exhibits to the Registration Statement or in the Prospectus or in documents incorporated by reference in the Prospectus with indicated amounts in the financial statements or accounting records of the Company and (excluding any questions of legal interpretation and, in the case of the letter delivered at the Time of Delivery, any exceptions disclosed in the letter delivered at the Effective Date) have found such information and percentages to be in agreement with the relevant accounting and financial information of the Company referred to in such

9

letter in the description of the procedures performed by them. If such letter discloses any material adverse decreases or increases, as the case may be, in the items specified in item (iii) (C) above which are not set forth in or contemplated by the Prospectus which, in the judgment of the Representatives, makes it impracticable or inadvisable to proceed with the public offering or the delivery of the Bonds on the terms and in the manner contemplated by the Prospectus, this Agreement and all obligations of the Underwriters hereunder may be cancelled by the Representatives by notifying the Company in the manner and with the effect provided below in the last sentence of this Section 6.

(d) At the Time of Delivery the Representatives shall have received a certificate of the Chairman, President, Vice President and principal financial officer, Vice President and principal accounting officer or Treasurer of the Company, dated as of the Time of Delivery, to the effect that the signer of such certificate has carefully examined the Registration Statement, the Prospectus and any amendment or supplement thereto and the Underwriting Agreement and that, in his opinion, at the time the Registration Statement became effective, the Registration Statement did not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading, and at the date of the Underwriting Agreement the Prospectus did not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading, and since the date of the Underwriting Agreement, no event has occurred which should have been set forth in an amendment of or supplement to the Prospectus which has not been so set forth; and no stop order suspending the effectiveness of the Registration Statement has been issued and no proceedings therefor have been instituted or threatened by the Commission; and to the further effect that all the representations and warranties contained in Section 2 hereof are true and correct, with the same force and effect as though expressly made at the Time of Delivery.

(e) At the Time of Delivery counsel for the Underwriters shall have been furnished with such documents and opinions as they may reasonably require for the purpose of enabling them to pass upon the sale of the Bonds as herein contemplated and related proceedings, or in order to evidence the accuracy or completeness of any of the representations or warranties, or the fulfillment of any of the conditions, herein contained; and all proceedings taken by the Company in connection with the sale of the Bonds as herein contemplated shall be satisfactory in form and substance to the Representatives and counsel for the Underwriters.

If any of the conditions specified in this Section shall not have been fulfilled when and as required by this Agreement to be fulfilled, this Agreement and all obligations of the Underwriters hereunder may be cancelled by the Representatives by notifying the Company of such cancellation in writing or by telecopy at any time at or prior to the Time of Delivery and any such cancellation shall be without liability of any party to any other party except as otherwise provided in this Agreement.

SECTION 7. Condition of Company's Obligations. The obligations of the Company to sell and deliver the Bonds are subject to the following conditions:
that at the Time of Delivery no stop order suspending the effectiveness of the Registration Statement shall have been issued or proceedings therefor initiated or threatened; that the order of the Illinois Commerce Commission, referred to in Section 2(k), shall be in full force and effect substantially in the form in which such order shall originally have been entered; and that the Indenture shall be qualified under the Trust Indenture Act.

SECTION 8. Indemnification. (a) The Company agrees to indemnify and hold harmless each Underwriter and each person, if any, who controls any Underwriter within the meaning of the Act or the 1934 Act, as follows:

(i) against any and all loss, liability, claim, damage and expense, whatsoever, arising out of any untrue statement or alleged untrue statement of a material fact contained in the registration statement as it became effective, or in any amendment thereto, or in the Registration Statement (or any amendment thereto), or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading, or arising out of any untrue statement or alleged untrue statement of a material fact contained in any preliminary prospectus or the Prospectus (or any

10

amendment or supplement thereto) or the omission or alleged omission therefrom of a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading, unless such untrue statement or omission or such alleged untrue statement or omission was made in reliance upon and in conformity with written information respecting the Underwriters furnished to the Company by or on behalf of any Underwriter through the Representatives expressly for use in the Registration Statement (or any amendment thereto) or the Prospectus (or any amendment or supplement thereto);

(ii) against any and all loss, liability, claim, damage and expense whatsoever to the extent of the aggregate amount paid in settlement of any litigation, commenced or threatened, or of any claim whatsoever based upon any such untrue statement or omission or any such alleged untrue statement or omission, if such settlement is effected with the written consent of the Company; and

(iii) against any and all expenses whatsoever reasonably incurred in investigating, preparing or defending against any litigation, commenced or threatened, or any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission, to the extent that any such expense is not paid under (i) or (ii) above, and, in the case of (i) above, unless such untrue statement or omission or such alleged untrue statement or omission was made in reliance upon and in conformity with written information respecting the Underwriters furnished to the Company by or on behalf of any Underwriter through the Representatives expressly for use in the Registration Statement (or any amendment thereto) or the Prospectus (or any amendment or supplement thereto), or, in the case of (ii) above, provided such settlement is effected with the written consent of the Company.

This indemnity agreement is subject to the condition that, insofar as it relates to any untrue statement, alleged untrue statement, omission or alleged omission made in a preliminary prospectus or preliminary prospectus supplement, but eliminated or remedied in the Prospectus, such indemnity agreement shall not inure to the benefit of any Underwriter from whom the person asserting any loss, liability, claim or damage purchases the Bonds which are the subject thereof (or to the benefit of any person who controls such Underwriter) if such Underwriter fails to send or give a copy of the Prospectus (excluding documents incorporated by reference) to such person prior to or together with written confirmation of the sale of such Bonds to such person and the delivery thereof would have constituted a defense to the claim by such person.

In no case shall the Company be liable under this indemnity agreement with respect to any claim made against any Underwriter or any such controlling person unless the Company shall be notified in writing of the nature of the claim within a reasonable time after the assertion thereof, but failure to so notify the Company shall not relieve it from any liability which it may have otherwise than on account of this indemnity agreement. The Company shall be entitled to participate at its own expense in the defense, or, if it so elects, within a reasonable time after receipt of such notice, to assume the defense of any suit brought to enforce any such claim, but if it so elects to assume the defense, such defense shall be conducted by counsel chosen by it and approved by the Underwriter or Underwriters or controlling person or persons, defendant or defendants in any suit so brought, which approval shall not be unreasonably withheld. In the event that the Company elects to assume the defense of any such suit and retains such counsel, the Underwriter or Underwriters or controlling person or persons, defendant or defendants in the suit shall thereafter bear the fees and expenses of any additional counsel retained by them. In the event that the parties to any such action (including impleaded parties) include both the Company and one or more Underwriters and any such Underwriter shall have been advised by counsel chosen by it and satisfactory to the Company that there may be one or more legal defenses available to it which are different from or additional to those available to the Company, the Company shall not have the right to assume the defense of such action on behalf of such Underwriter and will reimburse such Underwriter and any person controlling such Underwriter as aforesaid for the reasonable fees and expenses of any counsel retained by them, it being understood that the Company shall not, in connection with any one action or separate but similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances, be liable for the reasonable fees and expense of more than one separate firm of attorneys for all such Underwriters and controlling persons, which firm shall be designated in writing by the Representatives. The Company agrees to notify the Representatives within a reasonable time of the assertion

11

of any claim against it, any of its officers or directors or any person who controls the Company within the meaning of the Act or the 1934 Act, in connection with the sale of the Bonds.

(b) Each Underwriter severally agrees that it will indemnify and hold harmless the Company, its directors, and each of its officers who signed the Registration Statement and each person, if any, who controls the Company within the meaning of the Act or the 1934 Act, to the same extent as the indemnity contained in subsection (a) of this Section, but only with respect to statements or omissions made in the registration statement as it became effective, or in any amendment thereto, or in the Registration Statement (or any amendment thereto) or the Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with written information respecting the Underwriters furnished to the Company by or on behalf of such Underwriter through the Representatives expressly for use in the Registration Statement (or any amendment thereto) or the Prospectus (or any amendment or supplement thereto). In case any action shall be brought against the Company or any person so indemnified based on the Registration Statement (or any amendment thereto) or the Prospectus (or any amendment or supplement thereto) and in respect of which indemnity may be sought against any Underwriter, such Underwriter shall have the rights and duties given to the Company, and the Company and each person so indemnified shall have the rights and duties given to the Underwriters, by the provisions of subsection (a) of this Section.

(c) The obligations of the Company under this Section 8 shall be in addition to any liability which the Company may otherwise have and shall extend, upon the same terms and conditions, to each person, if any, who controls any Underwriter within the meaning of the Act or the 1934 Act; and the obligations of the Underwriters under this Section 8 shall be in addition to any liability which the respective Underwriters may otherwise have and shall extend, upon the same terms and conditions, to each officer and director of the Company and to each person, if any, who controls the Company within the meaning of the Act or the 1934 Act.

SECTION 9. Representations, Warranties and Agreements to Survive Delivery. All representations, warranties and agreements contained in the Underwriting Agreement and/or contained in certificates of officers of the Company submitted pursuant hereto, shall remain operative and in full force and effect, regardless of any investigation made by or on behalf of any Underwriter or any controlling person of any Underwriter, or by or on behalf of the Company, and shall survive payment for and delivery of the Bonds.

SECTION 10. Effective Date of the Underwriting Agreement and Termination Thereof. (a) The Underwriting Agreement shall become effective at the time of the initial public offering by the Underwriters of any of the Bonds. The time of the initial public offering shall mean 12:00 noon, New York City time, on the first full business day after the Underwriting Agreement is executed or at such time as the Representatives may authorize the sale of the Bonds to the public by the Underwriters or other securities dealers, whichever shall first occur. The Representatives or the Company may prevent the Underwriting Agreement from becoming effective without liability of any party to any other party, except as otherwise provided in the Underwriting Agreement, by giving the notice indicated below in this Section prior to the time the Underwriting Agreement would otherwise become effective as herein provided.

(b) The Representatives shall have the right to terminate the Underwriting Agreement by giving the notice indicated below in this Section at any time at or prior to the Time of Delivery if (i) the Company shall have sustained since the respective dates as of which information is given in the Prospectus any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree; or (ii) since the respective dates as of which information is given in the Prospectus there shall have been any material increase in the long-term debt, or any material adverse change, or any development involving a prospective material adverse change, in or affecting the general business affairs, management, financial position, results of operations, or business prospects of the Company and its subsidiaries considered as one enterprise, otherwise than as set forth or contemplated in the Prospectus, the effect of which, in any such case described in clause (i) or
(ii), in the judgment of the Representatives makes it impracticable or inadvisable to proceed with the public offering or the delivery of the Bonds on the terms and in the manner contemplated in the Prospectus; or (iii) there shall have occurred the outbreak or escalation of hostilities involving in a significant way the armed

12

forces of the United States, or the declaration by the United States, on or after the date of the Underwriting Agreement, of a national emergency or war, or there shall have occurred a general suspension or limitation of trading in securities on the New York or American Stock Exchanges, or the establishment of minimum prices on either such Exchange, or a general moratorium on commercial banking activities in New York is declared by either federal or New York state authorities, the effect of which in the judgment of the Representatives makes it impracticable or inadvisable to proceed with the public offering or the delivery of the Bonds on the terms and in the manner contemplated in the Prospectus. If the Representatives shall so terminate the Underwriting Agreement, such termination shall be without liability of any party to any other party except as otherwise provided in the Underwriting Agreement.

(c) If the Representatives elect to prevent the Underwriting Agreement from becoming effective or to terminate the Underwriting Agreement as provided in this Section, the Company and each other Underwriter shall be notified promptly by the Representatives, by telephone or telegram, confirmed by letter. If the Company elects to prevent the Underwriting Agreement from becoming effective as provided in this Section, the Representatives shall be notified promptly by the Company by telephone or telegram, confirmed by letter.

SECTION 11. Default of Underwriters. If any one or more of the Underwriters shall fail at the Time of Delivery to purchase the amount of Bonds which it or they are obligated to purchase hereunder (the "Defaulted Bonds"), then the Representatives shall have the right, within 24 hours thereafter, to make arrangements for one or more of the non-defaulting Underwriters, or any other underwriters, to purchase all, but not less than all, of the Defaulted Bonds in such amounts as may be agreed upon and upon the terms herein set forth. If, however, during such 24 hours the Representatives shall not have completed such arrangements for the purchase of all of the Defaulted Bonds, then the Company shall be entitled to a further period of 24 hours within which to procure another party of parties satisfactory to the Representatives to purchase all of such Defaulted Bonds on such terms. If, after giving effect to any arrangements for the purchase of Defaulted Bonds by the Representatives and the Company as provided above, then:

(a) if the amount of Defaulted Bonds does not exceed 10% of the aggregate principal amount of the Bonds being sold hereunder, the non-defaulting Underwriters shall be obligated to purchase severally the full amount thereof in the proportions that their respective underwriting obligations hereunder bear to the underwriting obligations of all non-defaulting Underwriters, or

(b) if the amount of Defaulted Bonds exceeds 10% of the aggregate principal amount of the Bonds being sold hereunder, the Underwriting Agreement shall terminate without any liability on the part of the Company or any non-defaulting Underwriter.

The termination of the Underwriting Agreement pursuant to this Section shall be without liability on the part of the Company or any of said non-defaulting Underwriters, except for the respective obligations of the Company and the Underwriters pursuant to Section 8 and except that the Company shall be obligated to reimburse the Underwriters for their out-of-pocket expenses (including reasonable fees and disbursements of counsel for the Underwriters) incurred in connection with the offering if the Underwriting Agreement could have been terminated by the Representatives pursuant to Section 6 or 10(b).

Nothing herein shall relieve any Underwriter so defaulting from liability, if any, for such default.

In the event of a default by any one or more Underwriters as set forth in this Section, either the Representatives or the Company shall have the right to postpone the Time of Delivery for an additional period not exceeding 7 days in order that any required changes in the Registration Statement and Prospectus or in any other documents or arrangements may be effected.

SECTION 12. Notices. Except as otherwise provided in the Underwriting Agreement, all communications under the Underwriting Agreement shall be in writing, and, if sent to the Underwriters, shall be mailed, delivered or telecopied and confirmed to the address of the Representatives, as set forth in the Underwriting Agreement (except that any notice to an Underwriter pursuant to
Section 8 hereof shall be sent to it at its address set forth in the copies of the Underwriters' Questionnaires furnished to the Company), or, if sent to the Company shall be mailed or telecopied and confirmed to it at P.O. Box 190, Aurora, Illinois 60507-0190,

13

or delivered to it at 1844 Ferry Road, Naperville, Illinois, for the attention of Donald W. Lohrentz, Vice President.

SECTION 13. Parties. The Underwriting Agreement shall inure to the benefit of and be binding upon the Underwriters and the Company and their respective successors. Nothing expressed or mentioned in the Underwriting Agreement is intended or shall be construed to give any person, firm or corporation, other than the parties hereto and their respective successors and the controlling persons and the directors and officers referred to in Section 8, any legal or equitable right, remedy or claim under or in respect of the Underwriting Agreement or any provision herein contained; the Underwriting Agreement and all conditions and provisions hereof being intended to be and being for the sole and exclusive benefit of the parties hereto and their respective successors and said controlling persons, directors and officers and for the benefit of no other person, firm or corporation. No purchaser of any Bonds from any Underwriter shall be deemed to be a successor by reason merely of such purchase.

SECTION 14. Choice of Law. The Underwriting Agreement shall be construed in accordance with, and governed by, the laws of the State of Illinois.

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Nicor Gas Company Form 10-K Exhibit 4.19

SUPPLEMENTAL INDENTURE


DATED FEBRUARY 15, 1998


NORTHERN ILLINOIS GAS COMPANY

TO

HARRIS TRUST AND SAVINGS BANK
TRUSTEE UNDER INDENTURE DATED AS OF
JANUARY 1, 1954 AND SUPPLEMENTAL
INDENTURES THERETO


FIRST MORTGAGE BONDS
6.58% SERIES DUE FEBRUARY 15, 2028

This instrument was prepared by Donald W. Lohrentz, 1844 Ferry Road, Naperville, Illinois 60563-9600.

Return to: Nicor Gas Company
Attn: Joe Johnson
P.O. Box 140, Aurora, IL 60507-0190

THIS SUPPLEMENTAL INDENTURE, dated the fifteenth day of February, 1998, between NORTHERN ILLINOIS GAS COMPANY, a corporation organized and existing under the laws of the State of Illinois (hereinafter called the "Company"), and HARRIS TRUST AND SAVINGS BANK, an Illinois banking corporation, (hereinafter called the "Trustee"), as Trustee under an Indenture dated as of January 1, 1954, as supplemented by Supplemental Indentures dated, respectively, February 9, 1954, April 1, 1956, June 1, 1959, July 1, 1960, June 1, 1963, July 1, 1963, August 1, 1964, August 1, 1965, May 1, 1966, August 1, 1966, July 1, 1967, June 1, 1968, December 1, 1969, August 1, 1970, June 1, 1971, July 1, 1972, July 1, 1973, April 1, 1975, April 30, 1976, April 30, 1976, July 1, 1976, August 1, 1976, December 1, 1977, January 15, 1979, December 1, 1981, March 1, 1983, October 1, 1984, December 1, 1986, March 15, 1988, July 1, 1988, July 1, 1989, July 15, 1990, August 15, 1991, July 15, 1992, February 1, 1993, March 15, 1993, May 1, 1993, July 1, 1993, August 15, 1994, October 15, 1995, May 10, 1996, August 1, 1996, June 1, 1997 and October 15, 1997, such Indenture dated as of January 1, 1954, as so supplemented, being hereinafter called the "Indenture."

WITNESSETH:

WHEREAS, the Indenture provides for the issuance from time to time thereunder, in series, of bonds of the Company for the purposes and subject to the limitations therein specified; and

WHEREAS, the Company desires, by this Supplemental Indenture, to create an additional series of bonds to be issuable under the Indenture, such bonds to be designated "First Mortgage Bonds, 6.58% Series due February 15, 2028" (hereinafter called the "bonds of this Series"), and the terms and provisions to be contained in the bonds of this Series or to be otherwise applicable thereto to be as set forth in this Supplemental Indenture; and

WHEREAS, the forms, respectively, of the bonds of this Series, and Trustee's certificate to be endorsed on all bonds of this Series, are to be substantially as follows:

(FORM OF FACE OF BOND)

NO. RU _____ $________

NORTHERN ILLINOIS GAS COMPANY

FIRST MORTGAGE BOND, 6.58% SERIES DUE FEBRUARY 15, 2028

NORTHERN ILLINOIS GAS COMPANY, an Illinois corporation (hereinafter called the "Company"), for value received, hereby promises to pay to or registered assigns, the sum of Dollars, on the fifteenth day of February, 2028, and to pay to the registered owner hereof interest on said sum from the date hereof until said sum shall be paid, at the rate of six and fifty-eight hundredths per centum (6.58%) per annum, payable semiannually on the fifteenth day of February and the fifteenth day of August in each

2

year. Both the principal of and the interest on this bond shall be payable at the office or agency of the Company in the City of Chicago, State of Illinois, or, at the option of the registered owner, at the office or agency of the Company in the Borough of Manhattan, The City and State of New York, in any coin or currency of the United States of America which at the time of payment is legal tender for the payment of public and private debts. Any installment of interest on the bonds may, at the Company's option, be paid by mailing checks for such interest payable to or upon the written order of the person entitled thereto to the address of such person as it appears on the registration books.

So long as there is no existing default in the payment of interest on this bond, the interest so payable on any interest payment date will be paid to the person in whose name this bond is registered on the February 1 or the August 1 (whether or not a business day), as the case may be, next preceding such interest payment date. If and to the extent that the Company shall default in the payment of interest due on such interest payment date, such defaulted interest shall be paid to the person in whose name this bond is registered on the record date fixed, in advance, by the Company for the payment of such defaulted interest.

Additional provisions of this bond are set forth on the reverse hereof.

This bond shall not be entitled to any security or benefit under the Indenture or be valid or become obligatory for any purpose unless and until it shall have been authenticated by the execution by the Trustee, or its successor in trust under the Indenture, of the certificate endorsed hereon.

IN WITNESS WHEREOF, Northern Illinois Gas Company has caused this bond to be executed in its name by its Chairman, President, or a Vice President, manually or by facsimile signature, and has caused its corporate seal to be impressed hereon or a facsimile thereof to be imprinted hereon and to be attested by its Secretary or its Assistant Secretary, manually or by facsimile signature.

Dated

NORTHERN ILLINOIS GAS COMPANY

By


President

ATTEST:


Secretary

3

(FORM OF TRUSTEE'S CERTIFICATE OF AUTHENTICATION)

This bond is one of the bonds of the series designated therein, referred to and described in the within-mentioned Supplemental Indenture dated February 15, 1998.

HARRIS TRUST AND SAVINGS,
TRUSTEE

By


Authorized Officer

(FORM OF REVERSE SIDE OF BOND)

This bond is one, of the series hereinafter specified, of the bonds issued and to be issued in series from time to time under and in accordance with and secured by an Indenture dated as of January 1, 1954, to Harris Trust and Savings Bank, as Trustee, as supplemented by certain indentures supplemental thereto, executed and delivered to the Trustee; and this bond is one of a series of such bonds, designated "Northern Illinois Gas Company First Mortgage Bonds, 6.58% Series due February 15, 2028" (herein called "bonds of this Series"), the issuance of which is provided for by a Supplemental Indenture dated February 15, 1998 (hereinafter called the "Supplemental Indenture"), executed and delivered by the Company to the Trustee. The term "Indenture", as hereinafter used, means said Indenture dated as of January 1, 1954, and all indentures supplemental thereto from time to time in effect. Reference is made to the Indenture for a description of the property mortgaged and pledged, the nature and extent of the security, the rights of the holders and registered owners of said bonds, of the Company and of the Trustee in respect of the security, and the terms and conditions governing the issuance and security of said bonds.

With the consent of the Company and to the extent permitted by and as provided in the Indenture, modifications or alterations of the Indenture or of any supplemental indenture and of the rights and obligations of the Company and of the holders and registered owners of the bonds may be made, and compliance with any provision of the Indenture or of any supplemental indenture may be waived, by the affirmative vote of the holders and registered owners of not less than sixty-six and two-thirds per centum (66 2/3%) in principal amount of the bonds then outstanding under the Indenture, and by the affirmative vote of the holders and registered owners of not less than sixty-six and two-thirds per centum (66 2/3%) in principal amount of the bonds of any series then outstanding under the Indenture and affected by such modification or alteration, in case one or more but less than all of the series of bonds then outstanding under the Indenture are so affected, but in any case excluding bonds disqualified from voting by reason of the Company's interest therein as provided in the Indenture; subject, however, to the condition, among other conditions stated in the Indenture, that no such modification or alteration shall be made which, among other things, will permit the

4

extension of the time or times of payment of the principal of or the interest on this bond, or the reduction in the principal amount hereof or in the rate of interest hereon, or any other modification in the terms of payment of such principal or interest, which terms of payment are unconditional, or, otherwise than as permitted by the Indenture, the creation of any lien ranking prior to or on a parity with the lien of the Indenture with respect to any of the mortgaged property, all as more fully provided in the Indenture.

The bonds of this Series may not be called for redemption by the Company.

In case of certain completed defaults specified in the Indenture, the principal of this bond may be declared or may become due and payable in the manner and with the effect provided in the Indenture.

No recourse shall be had for the payment of the principal of or the interest on this bond, or for any claim based hereon, or otherwise in respect hereof or of the Indenture, to or against any incorporator, stockholder, officer or director, past, present or future, of the Company or of any predecessor or successor corporation, either directly or through the Company or such predecessor or successor corporation, under any constitution or statute or rule of law, or by the enforcement of any assessment or penalty, or otherwise, all such liability of incorporators, stockholders, directors and officers being waived and released by the registered owner hereof by the acceptance of this bond and being likewise waived and released by the terms of the Indenture, all as more fully provided therein.

This bond is transferable by the registered owner hereof, in person or by duly authorized attorney, at the office or agency of the Company in the City of Chicago, State of Illinois, or, at the option of the registered owner, at the office or agency of the Company in the Borough of Manhattan, The City and State of New York, upon surrender and cancellation of this bond; and thereupon a new registered bond or bonds without coupons of the same aggregate principal amount and series will, upon the payment of any transfer tax or taxes payable, be issued to the transferee in exchange herefor. The Company shall not be required to exchange or transfer this bond if this bond or a portion hereof has been selected for redemption.

(END OF BOND FORM)

and

WHEREAS, all acts and things necessary to make this Supplemental Indenture, when duly executed and delivered, a valid, binding and legal instrument in accordance with its terms and for the purposes herein expressed, have been done and performed, and the execution and delivery of this Supplemental Indenture have in all respects been duly authorized;

NOW, THEREFORE, in consideration of the premises and of the sum of one dollar paid by the Trustee to the Company, and for other good and valuable considerations, the receipt of which is hereby acknowledged, for the purpose of securing the due and punctual payment of the principal of and the interest and premium, if any, on all bonds

5

which shall be issued under the Indenture, and for the purpose of securing the faithful performance and observance of all the covenants and conditions set forth in the Indenture and in all indentures supplemental thereto, the Company by these presents does grant, bargain, sell, transfer, assign, pledge, mortgage, warrant and convey unto Harris Trust and Savings Bank, as Trustee, and its successor or successors in the trust hereby created, all property, real and personal (other than property expressly excepted from the lien and operation of the Indenture), which, at the actual date of execution and delivery of this Supplemental Indenture, is solely used or held for use in the operation by the Company of its gas utility system and in the conduct of its gas utility business and all property, real and personal, used or useful in the gas utility business (other than property expressly excepted from the lien and operation of the Indenture) acquired by the Company after the actual date of execution and delivery of this Supplemental Indenture or (subject to the provisions of Section 16.03 of the Indenture) by any successor corporation after such execution and delivery, and it is further agreed by and between the Company and the Trustee as follows:

ARTICLE I

BONDS OF THIS SERIES

SECTION 1. The bonds of this Series shall, as hereinbefore recited, be designated as the Company's "First Mortgage Bonds, 6.58% Series due February 15, 2028." The bonds of this Series which may be issued and outstanding shall not exceed $50,000,000 in aggregate principal amount, exclusive of bonds of such series authenticated and delivered pursuant to the provisions of Section 4.12 of the Indenture.

SECTION 2. The bonds of this Series shall be registered bonds without coupons, and the form of such bonds, and of the Trustee's certificate of authentication to be endorsed on all bonds of this Series, shall be substantially as hereinbefore recited, respectively.

SECTION 3. The bonds of this Series shall be issued in the denomination of $1,000 each and in such multiple or multiples thereof as shall be determined and authorized by the Board of Directors of the Company or by any officer or officers of the Company authorized by the Board of Directors to make such determination, the authorization of the denomination of any bond to be conclusively evidenced by the execution thereof on behalf of the Company. The bonds of this Series shall be numbered, RU-1 and consecutively upwards, or in such other appropriate manner as shall be determined and authorized by the Board of Directors of the Company.

All bonds of this Series shall be dated February 15, 1998, except that each bond issued on or after the first payment of interest thereon shall be dated as of the date of the interest payment date thereof to which interest shall have been paid on the bonds of such series next preceding the date of issue, unless issued on an interest payment date to which interest shall have been so paid, in which event such bonds shall be dated as of the date of issue; provided, however, that bonds issued on or after February 1 and before the next succeeding February 15 or on or after August 1 and before the next

6

succeeding August 15 shall be dated the next succeeding interest payment date if interest shall have been paid to such date. All bonds of this Series shall mature February 15, 2028, and shall bear interest at the rate of 6.58% per annum until the principal thereof shall be paid. Such interest shall be calculated on the basis of a 360-day year consisting of twelve 30-day months and shall be payable semiannually on the fifteenth day of February and the fifteenth day of August in each year. So long as there is no existing default in the payment of interest on the bonds of this Series, such interest shall be payable to the person in whose name each such bond is registered on the February 1 or the August 1 (whether or not a business day), as the case may be, next preceding the respective interest payment dates; provided, however, if and to the extent that the Company shall default in the payment of interest due on such interest payment date, such defaulted interest shall be paid to the person in whose name each such bond is registered on the record date fixed, in advance, by the Company for the payment of such defaulted interest.

The principal of and interest on the bonds of this Series shall be payable in any coin or currency of the United States of America which at the time of payment is legal tender for the payment of public and private debts, and shall be payable at the office or agency of the Company in the City of Chicago, State of Illinois, or, at the option of the registered owner, at the office or agency of the Company in the Borough of Manhattan, The City and State of New York. Any installment of interest on the bonds may, at the Company's option, be paid by mailing checks for such interest payable to or upon the written order of the person entitled thereto to the address of such person as it appears on the registration books. The bonds of this Series shall be registrable, transferable and exchangeable in the manner provided in Sections 4.08 and 4.09 of the Indenture, at either of such offices or agencies.

SECTION 4. The bonds of this Series may not be called for redemption by the Company.

SECTION 5. No sinking fund is to be provided for the bonds of this Series.

7

ARTICLE II

MISCELLANEOUS PROVISIONS

SECTION 1. This Supplemental Indenture is executed by the Company and the Trustee pursuant to provisions of Section 4.02 of the Indenture and the terms and conditions hereof shall be deemed to be a part of the terms and conditions of the Indenture for any and all purposes. The Indenture, as heretofore supplemented and as supplemented by this Supplemental Indenture, is in all respects ratified and confirmed.

SECTION 2. This Supplemental Indenture shall bind and, subject to the provisions of Article XVI of the Indenture, inure to the benefit of the respective successors and assigns of the parties hereto.

SECTION 3. Although this Supplemental Indenture is dated February 15, 1998, it shall be effective only from and after the actual time of its execution and delivery by the Company and the Trustee on the date indicated by their respective acknowledgments hereto annexed.

SECTION 4. This Supplemental Indenture may be simultaneously executed in any number of counterparts, and all such counterparts executed and delivered, each as an original, shall constitute but one and the same instrument.

8

IN WITNESS WHEREOF, Northern Illinois Gas Company has caused this Supplemental Indenture to be executed in its name by its President, a Vice President, or Treasurer, and its corporate seal to be hereunto affixed and attested by its Secretary or its Assistant Secretary, and Harris Trust and Savings Bank, as Trustee under the Indenture, has caused this Supplemental Indenture to be executed in its name by one of its Vice Presidents, and its seal to be hereunto affixed and attested by one of its Assistant Secretaries, all as of the day and year first above written.

NORTHERN ILLINOIS GAS COMPANY

BY

Vice President and Treasurer
ATTEST:
Assistant Secretary

HARRIS TRUST AND SAVINGS BANK,
as Trustee

BY

Vice President
ATTEST:
Assistant Secretary

9

STATE OF ILLINOIS SS:
COUNTY OF DUPAGE

I, Catherine A. Gengler, a Notary Public in the State aforesaid, DO HEREBY CERTIFY that Donald W. Lohrentz, Vice President and Treasurer of Northern Illinois Gas Company, an Illinois corporation, one of the parties described in and which executed the foregoing instrument, and Alexander C. Allison, Assistant Secretary of said corporation, who are both personally known to me to be the same persons whose names are subscribed to the foregoing instrument as such Vice President and Treasurer and Assistant Secretary, respectively, and who are both personally known to me to be Vice President and Treasurer and the Assistant Secretary, respectively, of said corporation, appeared before me this day in person and severally acknowledged that they signed, sealed, executed and delivered said instrument as their free and voluntary act as such Vice President and Treasurer and Assistant Secretary, respectively, of said corporation, and as the free and voluntary act of said corporation, for the uses and purposes therein set forth.

GIVEN under my hand and notarial seal this 19th day of February A.D. 1998.

Notary Public

My Commission expires August 4, 2001

10

STATE OF ILLINOIS SS:
COUNTY OF COOK

I, Kimberley Lange, a Notary Public in and for said County, in the State aforesaid, DO HEREBY CERTIFY that J. Bartolini, Vice President of Harris Trust and Savings Bank, an Illinois banking corporation, one of the parties described in and which executed the foregoing instrument, and D. G. Donovan, an Assistant Secretary of said banking association, who are both personally known to me to be the same persons whose names are subscribed to the foregoing instrument as such Vice President and Assistant Secretary, respectively, and who are both personally known to me to be a Vice President and an Assistant Secretary, respectively, of said banking association, appeared before me this day in person and severally acknowledged that they signed, sealed, executed and delivered said instrument as their free and voluntary act as such Vice President and Assistant Secretary, respectively, of said banking association, and as the free and voluntary act of said banking association, for the uses and purposes therein set forth.

GIVEN under my hand and notarial seal this 19th day of February A.D. 1998.

Notary Public

My Commission expires November 7, 2001

11

RECORDING DATA

This Supplemental Indenture was recorded on February 20 and 23, 1998, in the office of the Recorder of Deeds in certain counties in the State of Illinois, as follows:

    COUNTY        BOOK    PAGE  DOCUMENT NO.
    ------        ----    ----  ------------
Adams
Boone
Bureau
Carroll
Champaign
Cook
DeKalb
DeWitt
DuPage
Ford
Grundy
Hancock
Henderson
Henry
Iroquois
Jo Daviess
Kane
Kankakee
Kendall
Lake
La Salle
Lee
Livingston
McHenry
McLean
Mercer
Ogle
Platt
Pike
Rock Island
Stephenson
Tazewell
Vermillon
Whiteside
Will
Winnebago
Woodford


                                                                                      Nicor Gas Company
                                                                                      Form 10-K
                                                                                      Exhibit 12.01


                                            Nicor Gas Company
                     COMPUTATION OF CONSOLIDATED RATIO OF EARNINGS TO FIXED CHARGES
                                               (Thousands)

                                                                      Year Ended December 31
                                                        1997      1996      1995       1994      1993

Earnings available to cover fixed charges:

 Net income                                         $  106,922 $ 107,106 $  85,448  $  93,078 $  94,935

 Add:  Income taxes                                     64,714    63,579    49,881     50,958    52,890

       Fixed charges                                    46,886    46,747    39,400     37,729    40,960

       Allowance for funds used
          during construction                              (11)       (5)     (911)      (151)      (64)

 Total                                              $  218,511 $ 217,427 $ 173,818  $ 181,614 $ 188,721


Fixed charges:

 Interest on debt                                   $   45,246 $  43,762 $  38,129  $  36,726 $  38,949

 Other interest charges and
    amortization of debt discount,
    premium and expense, net                             1,640     2,985     1,271      1,003     2,011

 Total                                              $   46,886 $  46,747 $  39,400  $  37,729 $  40,960


Ratio of earnings to fixed charges                        4.66      4.65      4.41       4.81      4.61


Nicor Gas Company Form 10-K Exhibit 23.01

CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS

As independent public accountants, we hereby consent to the incorporation by reference of our report, dated January 27, 1998, included in this Form 10-K, into the company's previously filed Form S-3 Registration Statement in connection with the Nicor Gas Company $175,000,000 First Mortgage Bond shelf filing (No. 333-42559).

ARTHUR ANDERSEN LLP

Chicago, Illinois
March 23, 1998


Nicor Gas Company Form 10-K Exhibit 24.01

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

That the undersigned, a Director, Officer, or Director and Officer of Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois corporation, does hereby constitute and appoint D. L. CYRANOSKI and G. M. BEHRENS, and each of them, the undersigned's true and lawful attorneys and agents, each with full power and authority (acting alone and without the other) to execute in the name and on behalf of the undersigned as such Director, Officer, or Director and Officer, the 1997 Annual Report on Form 10-K (and such amendment or amendments thereto as may be necessary) to be filed pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934, hereby granting to such attorneys and agents, and each of them, full power of substitution and revocation in the premises; and hereby ratifying and confirming all that such attorneys and agents, or any of them, may do or cause to be done by virtue of these presents.

IN WITNESS WHEREOF, I have hereunto signed this Power of Attorney this 27th day of January, 1998.

ROBERT M. BEAVERS, JR.
Robert M. Beavers, Jr.

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

That the undersigned, a Director, Officer, or Director and Officer of Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois corporation, does hereby constitute and appoint D. L. CYRANOSKI and G. M. BEHRENS, and each of them, the undersigned's true and lawful attorneys and agents, each with full power and authority (acting alone and without the other) to execute in the name and on behalf of the undersigned as such Director, Officer, or Director and Officer, the 1997 Annual Report on Form 10-K (and such amendment or amendments thereto as may be necessary) to be filed pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934, hereby granting to such attorneys and agents, and each of them, full power of substitution and revocation in the premises; and hereby ratifying and confirming all that such attorneys and agents, or any of them, may do or cause to be done by virtue of these presents.

IN WITNESS WHEREOF, I have hereunto signed this Power of Attorney this 27th day of January, 1998.

BRUCE P. BICKNER
Bruce P. Bickner

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

That the undersigned, a Director, Officer, or Director and Officer of Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois corporation, does hereby constitute and appoint D. L. CYRANOSKI and G. M. BEHRENS, and each of them, the undersigned's true and lawful attorneys and agents, each with full power and authority (acting alone and without the other) to execute in the name and on behalf of the undersigned as such Director, Officer, or Director and Officer, the 1997 Annual Report on Form 10-K (and such amendment or amendments thereto as may be necessary) to be filed pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934, hereby granting to such attorneys and agents, and each of them, full power of substitution and revocation in the premises; and hereby ratifying and confirming all that such attorneys and agents, or any of them, may do or cause to be done by virtue of these presents.

IN WITNESS WHEREOF, I have hereunto signed this Power of Attorney this 27th day of January, 1998.

JOHN H. BIRDSALL, III
John H. Birdsall, III

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

That the undersigned, a Director, Officer, or Director and Officer of Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois corporation, does hereby constitute and appoint D. L. CYRANOSKI and G. M. BEHRENS, and each of them, the undersigned's true and lawful attorneys and agents, each with full power and authority (acting alone and without the other) to execute in the name and on behalf of the undersigned as such Director, Officer, or Director and Officer, the 1997 Annual Report on Form 10-K (and such amendment or amendments thereto as may be necessary) to be filed pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934, hereby granting to such attorneys and agents, and each of them, full power of substitution and revocation in the premises; and hereby ratifying and confirming all that such attorneys and agents, or any of them, may do or cause to be done by virtue of these presents.

IN WITNESS WHEREOF, I have hereunto signed this Power of Attorney this 27th day of January, 1998.

W. H. CLARK
W. H. Clark

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

That the undersigned, a Director, Officer, or Director and Officer of Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois corporation, does hereby constitute and appoint D. L. CYRANOSKI and G. M. BEHRENS, and each of them, the undersigned's true and lawful attorneys and agents, each with full power and authority (acting alone and without the other) to execute in the name and on behalf of the undersigned as such Director, Officer, or Director and Officer, the 1997 Annual Report on Form 10-K (and such amendment or amendments thereto as may be necessary) to be filed pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934, hereby granting to such attorneys and agents, and each of them, full power of substitution and revocation in the premises; and hereby ratifying and confirming all that such attorneys and agents, or any of them, may do or cause to be done by virtue of these presents.

IN WITNESS WHEREOF, I have hereunto signed this Power of Attorney this 27th day of January, 1998.

DENNIS J. KELLER
Dennis J. Keller

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

That the undersigned, a Director, Officer, or Director and Officer of Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois corporation, does hereby constitute and appoint D. L. CYRANOSKI and G. M. BEHRENS, and each of them, the undersigned's true and lawful attorneys and agents, each with full power and authority (acting alone and without the other) to execute in the name and on behalf of the undersigned as such Director, Officer, or Director and Officer, the 1997 Annual Report on Form 10-K (and such amendment or amendments thereto as may be necessary) to be filed pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934, hereby granting to such attorneys and agents, and each of them, full power of substitution and revocation in the premises; and hereby ratifying and confirming all that such attorneys and agents, or any of them, may do or cause to be done by virtue of these presents.

IN WITNESS WHEREOF, I have hereunto signed this Power of Attorney this 27th day of January, 1998.

CHARLES S. LOCKE
Charles S. Locke

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

That the undersigned, a Director, Officer, or Director and Officer of Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois corporation, does hereby constitute and appoint D. L. CYRANOSKI and G. M. BEHRENS, and each of them, the undersigned's true and lawful attorneys and agents, each with full power and authority (acting alone and without the other) to execute in the name and on behalf of the undersigned as such Director, Officer, or Director and Officer, the 1997 Annual Report on Form 10-K (and such amendment or amendments thereto as may be necessary) to be filed pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934, hereby granting to such attorneys and agents, and each of them, full power of substitution and revocation in the premises; and hereby ratifying and confirming all that such attorneys and agents, or any of them, may do or cause to be done by virtue of these presents.

IN WITNESS WHEREOF, I have hereunto signed this Power of Attorney this 27th day of January, 1998.

SIDNEY R. PETERSEN
Sidney R. Petersen

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

That the undersigned, a Director, Officer, or Director and Officer of Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois corporation, does hereby constitute and appoint D. L. CYRANOSKI and G. M. BEHRENS, and each of them, the undersigned's true and lawful attorneys and agents, each with full power and authority (acting alone and without the other) to execute in the name and on behalf of the undersigned as such Director, Officer, or Director and Officer, the 1997 Annual Report on Form 10-K (and such amendment or amendments thereto as may be necessary) to be filed pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934, hereby granting to such attorneys and agents, and each of them, full power of substitution and revocation in the premises; and hereby ratifying and confirming all that such attorneys and agents, or any of them, may do or cause to be done by virtue of these presents.

IN WITNESS WHEREOF, I have hereunto signed this Power of Attorney this 27th day of January, 1998.

DANIEL R. TOLL
Daniel R. Toll

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

That the undersigned, a Director, Officer, or Director and Officer of Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois corporation, does hereby constitute and appoint D. L. CYRANOSKI and G. M. BEHRENS, and each of them, the undersigned's true and lawful attorneys and agents, each with full power and authority (acting alone and without the other) to execute in the name and on behalf of the undersigned as such Director, Officer, or Director and Officer, the 1997 Annual Report on Form 10-K (and such amendment or amendments thereto as may be necessary) to be filed pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934, hereby granting to such attorneys and agents, and each of them, full power of substitution and revocation in the premises; and hereby ratifying and confirming all that such attorneys and agents, or any of them, may do or cause to be done by virtue of these presents.

IN WITNESS WHEREOF, I have hereunto signed this Power of Attorney this 27th day of January, 1998.

PATRICIA A. WIER
Patricia A. Wier


ARTICLE UT
This schedule contains summary financial information extracted from the consolidated statement of income, the consolidated balance sheet, the consolidated statement of capitalization, the consolidated statement of retained earnings and the consolidated statement of cash flows and is qualified in its entirety by reference to such financial statements.
MULTIPLIER: 1,000,000


PERIOD TYPE YEAR
FISCAL YEAR END DEC 31 1997
PERIOD END DEC 31 1997
BOOK VALUE PER BOOK
TOTAL NET UTILITY PLANT 1,630
OTHER PROPERTY AND INVEST 4
TOTAL CURRENT ASSETS 471
TOTAL DEFERRED CHARGES 0
OTHER ASSETS 84
TOTAL ASSETS 2,189
COMMON 76
CAPITAL SURPLUS PAID IN 108
RETAINED EARNINGS 497
TOTAL COMMON STOCKHOLDERS EQ 681
PREFERRED MANDATORY 8
PREFERRED 1
LONG TERM DEBT NET 521
SHORT TERM NOTES 0
LONG TERM NOTES PAYABLE 0
COMMERCIAL PAPER OBLIGATIONS 255
LONG TERM DEBT CURRENT PORT 25
PREFERRED STOCK CURRENT 1
CAPITAL LEASE OBLIGATIONS 0
LEASES CURRENT 0
OTHER ITEMS CAPITAL AND LIAB 697
TOT CAPITALIZATION AND LIAB 2,189
GROSS OPERATING REVENUE 1,731
INCOME TAX EXPENSE 62
OTHER OPERATING EXPENSES 1,520
TOTAL OPERATING EXPENSES 1,582
OPERATING INCOME LOSS 149
OTHER INCOME NET 5
INCOME BEFORE INTEREST EXPEN 154
TOTAL INTEREST EXPENSE 47
NET INCOME 107
PREFERRED STOCK DIVIDENDS 1
EARNINGS AVAILABLE FOR COMM 106
COMMON STOCK DIVIDENDS 108
TOTAL INTEREST ON BONDS 40
CASH FLOW OPERATIONS 204
EPS PRIMARY 0 1
EPS DILUTED 0
1 Nicor Gas is a wholly owned subsidiary of Nicor Inc. Earning and dividends per share information is therefore omitted.