If your shares are held in “street name” by a bank, broker or other nominee and you wish to vote in person at the special meeting, you must obtain a legal proxy from your bank, broker or other nominee and present it to the inspector of election with your ballot when you vote at the special meeting. Please also bring to the special meeting your account statement evidencing your beneficial ownership of Spectra Energy common stock as of the record date and valid government-issued photo identification.

The accompanying proxy statement/prospectus provides a detailed description of the merger agreement, the merger, the merger proposal and the related agreements and transactions. We urge you to read the accompanying proxy statement/prospectus, including any documents incorporated by reference into the accompanying proxy statement/prospectus, and its annexes carefully and in their entirety. If you have any questions concerning the merger, the merger proposal, the other proposals or the accompanying proxy statement/prospectus, would like additional copies of the accompanying proxy statement/prospectus or need help voting your shares, please contact Spectra Energy’s proxy solicitor at the address and telephone numbers listed below:

INNISFREE M&A INCORPORATED

501 Madison Avenue, 20 ^th Floor

New York, NY 10022

1-877-800-5185 (toll-free from the U.S. and Canada)

1-412-232-3651 (from other locations)

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QUESTIONS AND ANSWERS ABOUT THE MERGER AND THE SPECIAL MEETING

The following questions and answers are intended to address briefly some commonly asked questions regarding the merger and matters to be addressed at the special meeting. These questions and answers may not address all questions that may be important to you. To better understand these matters, and for a description of the legal terms governing the merger, you should carefully read this entire proxy statement/prospectus, including the attached annexes, as well as the documents that have been incorporated by reference into this proxy statement/prospectus. For more information, see the section entitled “Where You Can Find Additional Information.”

Spectra Energy is holding a special meeting to obtain the stockholder approval necessary to adopt the merger agreement, among other matters. Approval of the merger proposal by Spectra Energy stockholders is required for the completion of the merger. Spectra Energy stockholders are also being asked to consider and vote on a proposal to approve, on an advisory (non-binding) basis, certain specified compensation that will or may be paid by Spectra Energy to its named executive officers that is based on or otherwise relates to the merger (the advisory compensation proposal). Spectra Energy’s named executive officers are identified under the section entitled “ The Merger Proposal—Interests of Spectra Energy’s Directors and Executive Officers in the Merger .”

In addition, the merger cannot be completed unless Enbridge shareholders approve the issuance of Enbridge common shares in connection with the merger, which we refer to as the “Enbridge common share issuance,” and an amendment to the by-laws of Enbridge as set forth in Exhibit A to the merger agreement, which we refer to as the “by-law amendment.” Enbridge will be holding a special meeting of its shareholders (which we refer to as the “Enbridge special meeting”) to vote on the proposals necessary to complete the merger and other matters to be considered by the Enbridge shareholders at such special meeting. Enbridge will separately prepare a management information circular in accordance with applicable Canadian securities and corporate laws, which we refer to as the “management information circular,” and distribute such management information circular to its shareholders in connection with the Enbridge special meeting.

This proxy statement/prospectus constitutes both a proxy statement of Spectra Energy and a prospectus of Enbridge. It is a proxy statement because the Spectra Energy board of directors is soliciting proxies from its stockholders. It is a prospectus because Enbridge will issue to Spectra Energy stockholders its common shares as consideration for the exchange of outstanding shares of Spectra Energy common stock in the merger.

Your vote is very important. We encourage you to submit a proxy to have your shares of Spectra Energy common stock voted as soon as possible.

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No fractional Enbridge common shares will be issued upon the conversion of Spectra Energy common stock. All fractional Enbridge common shares that a holder of eligible shares would be otherwise entitled to receive pursuant to the merger agreement will be aggregated and rounded to three decimal places. Any holder of eligible shares otherwise entitled to receive a fractional Enbridge common share will be entitled to receive a cash payment, without interest, in lieu of any such fractional share, which payment will be calculated by the exchange agent and will represent such holder’s proportionate interest in an Enbridge common share based on the average (rounded to the nearest thousandth) of the closing trading prices of Enbridge common shares on the NYSE, as reported by the NYSE for the 10 trading days ending on, and including, the trading day that is three trading days prior to the date on which the merger is completed, which we refer to as the “closing date.” No holder of eligible shares will be entitled by virtue of the right to receive cash in lieu of fractional Enbridge common shares to any dividends, voting rights or any other rights in respect of any fractional Enbridge common share.

Based on the closing price of Enbridge common shares on the NYSE on September 2, 2016, the last full trading day before the announcement of the merger agreement, the per share value of Spectra Energy common stock implied by the merger consideration was $40.33. Based on the closing price of Enbridge common shares on the NYSE on [●], the most recent practicable date prior to the date of this proxy statement/prospectus, the per share value of Spectra Energy common stock implied by the merger consideration was $[●]. The implied value of the merger consideration will fluctuate, however, as the market price of Enbridge common shares fluctuates, because the merger consideration that is payable per share of Spectra Energy common stock is a fixed fraction of an Enbridge common share. As a result, the value of the merger consideration that Spectra Energy stockholders will receive upon the completion of the merger could be greater than, less than or the same as the value of the merger consideration on the date of this proxy statement/prospectus or at the time of the special meeting. Accordingly, you are encouraged to obtain current stock price quotations for Spectra Energy common stock and Enbridge common shares before deciding how to vote with respect to the merger proposal. Spectra Energy common stock trades on the NYSE under the ticker symbol “SE” and Enbridge common shares trade on the NYSE and the TSX under the ticker symbol “ENB.” The price of Enbridge common shares on the NYSE is reported in U.S. dollars, while the price of Enbridge common shares on the TSX is reported in Canadian dollars.

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The approval of the merger proposal is a condition to the obligations of Spectra Energy and Enbridge to complete the merger. The approval of the advisory compensation proposal is not a condition to the obligations of Spectra Energy or Enbridge to complete the merger and is not binding on Spectra Energy or Enbridge following the merger.

Accordingly, the Spectra Energy board of directors recommends that you vote:

For a discussion of each proposal, see the sections entitled “ The Merger Proposal—Spectra Energy’s Reasons for the Merger; Recommendation of the Spectra Energy Board of Directors,” and “The Advisory Compensation Proposal.”

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If your shares are held in “street name” by a bank, broker or other nominee, you should have received a voting instruction form from your bank, broker or other nominee and you should follow the instructions given by that institution. If you are a “street name” owner and have a legal proxy from the stockholder of record, you may vote in person at the special meeting.

If you fail to instruct your bank, broker or other nominee how to vote, that failure will have the same effect as a vote “AGAINST” the merger proposal. If you submit an instruction to your bank, broker or other nominee that fails to vote “FOR” the advisory compensation proposal, it will have the same effect as a vote “AGAINST” the advisory compensation proposal. If you fail to submit any instruction to your bank, broker or other nominee, it will have no effect on the advisory compensation proposal, assuming that a quorum is otherwise present.

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If you choose to revoke your proxy by written notice or submit a later-dated proxy, you must do so by [●].

If your shares are held in “street name” by your bank, broker or other nominee and you have directed such bank, broker or other nominee to vote your shares, you should instruct such bank, broker or other nominee to change your vote and follow the directions you receive from your bank, broker or other nominee in order to change or revoke your vote.

If you abstain from voting or submit an instruction to your bank, broker or other nominee that fails to vote “FOR” the advisory compensation proposal, it will have the same effect as a vote “AGAINST” the advisory compensation proposal. If you fail to submit any instruction to your bank, broker or other nominee, it will have no effect on the advisory compensation proposal, assuming that a quorum is otherwise present.

If you submit your proxy card but do not indicate how you want to vote on a particular proposal, your proxy will be counted as a vote “FOR” that proposal.

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Spectra Energy common stock held in “street name” with respect to which the beneficial owner fails to give voting instructions to the bank, broker or nominee, and Spectra Energy common stock with respect to which the beneficial owner otherwise fails to vote, will not be considered present and entitled to vote at the special meeting for the purpose of determining the presence of a quorum.

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As of the record date for the special meeting, the directors and executive officers of Spectra Energy owned, in the aggregate, approximately [●] shares of Spectra Energy common stock, representing approximately [●]% of the shares of Spectra Energy common stock then outstanding and entitled to vote at the special meeting.

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Enbridge common shares received by Spectra Energy stockholders in connection with the merger will be freely transferable except for shares issued to any stockholder deemed to be an “affiliate” of Enbridge for purposes of U.S. federal securities law. For more information, see the section entitled “ The Merger Proposal—Restrictions on Resales of Enbridge Common Shares Received in the Merger .”

Assuming the merger qualifies for the Intended Tax Treatment, the United States federal income tax consequences to U.S. holders (as defined herein) of Spectra Energy common stock generally are as follows:

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A Canadian Resident Holder (as defined in the section entitled “ The Merger Proposal—Certain Canadian Federal Income Tax Consequences of the Merger and the Canadian Exchange Offer ”) who disposes of his, her or its Spectra Energy common stock for Enbridge common shares pursuant to the merger will generally realize a capital gain (or capital loss) equal to the amount by which the fair market value of the Enbridge common shares received (and any cash received in lieu of a fractional Enbridge common share) exceeds (or is less than) the adjusted cost base of the Canadian Resident Holder’s Spectra Energy common stock determined immediately before the disposition and any reasonable costs of disposition.

However, a Canadian Resident Holder who disposes of his, her or its Spectra Energy common stock in consideration for Enbridge common shares pursuant to the Canadian exchange offer and files a valid tax election under Section 85 of the Income Tax Act (Canada) and all regulations promulgated thereunder from time to time, which we refer to as the “Canadian Tax Act,” jointly with Enbridge in accordance with the merger agreement and the Canadian Tax Act, may, wholly or partly defer the recognition of any capital gain that might otherwise arise on the disposition, to the extent and subject to the rules and restrictions in the Canadian Tax Act.

A Non-Canadian Resident Holder (as defined in the section entitled “ The Merger Proposal—Certain Canadian Federal Income Tax Consequences of the Merger and the Canadian Exchange Offer ”) will not be subject to tax under the Canadian Tax Act on any capital gain realized on a disposition of Spectra Energy common stock pursuant to the merger, or on a subsequent disposition of Enbridge common shares acquired in the merger, unless the relevant share is “taxable Canadian property,” and is not “treaty-protected property” (as those terms are defined in the Canadian Tax Act) of the Non-Canadian Resident Holder, at the time of the disposition.

You should read the sections entitled “The Merger Proposal—Certain U.S. Federal Income Tax Consequences” and “The Merger Proposal—Certain Canadian Federal Income Tax Consequences of the Merger and the Canadian Exchange Offer” and consult your own tax advisors regarding the United States federal income tax consequences of the merger to you in your particular circumstances, as well as tax consequences arising under the laws of any state, local or non-U.S. taxing jurisdiction.

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However, the merger consideration will be equitably adjusted to provide you and Enbridge with the same economic effect as contemplated by the merger agreement in the event of any reclassification, stock split (including a reverse stock split), stock dividend or distribution, recapitalization, merger or other similar transaction involving Spectra Energy common stock or Enbridge common shares prior to the completion of the merger.

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THE MERGER PROPOSAL

This section of the proxy statement/prospectus describes the various aspects of the merger and related matters. This section may not contain all of the information that is important to you. You should carefully read this entire proxy statement/prospectus and the documents incorporated by reference into this proxy statement/prospectus, including the full text of the merger agreement, a copy of which is attached to this proxy statement/prospectus as Annex A, for a more complete understanding of the merger. In addition, important business and financial information about each of Spectra Energy and Enbridge is included in or incorporated by reference into this proxy statement/prospectus. For a listing of the documents incorporated by reference into this proxy statement/prospectus, see the section entitled “Where You Can Find Additional Information.”

Transaction Structure

The merger agreement provides that, subject to the terms and conditions of the merger agreement, at the effective time, Merger Sub, a direct wholly owned subsidiary of Enbridge, will merge with and into Spectra Energy. As a result, Spectra Energy will survive the merger as a direct wholly owned subsidiary of Enbridge. The terms and conditions of the merger are contained in the merger agreement, which is described in this proxy statement/prospectus and attached to this proxy statement/prospectus as Annex A. You are encouraged to read the merger agreement carefully, as it is the legal document that governs the merger. All descriptions in this summary and elsewhere in this proxy statement/prospectus of the terms and conditions of the merger are qualified by reference to the merger agreement.

Merger Consideration

Upon the completion of the merger, each share of Spectra Energy common stock issued and outstanding immediately prior to the effective time (other than Spectra Energy common stock owned directly by Enbridge, Merger Sub or Spectra Energy, and in each case not held on behalf of third parties) will be automatically converted into the right to receive 0.984 of a validly issued, fully paid and non-assessable Enbridge common share (the merger consideration).

Based on the number of shares of Spectra Energy common stock outstanding as of [●], Enbridge will issue approximately [●] Enbridge common shares to Spectra Energy stockholders pursuant to the merger agreement. The actual number of Enbridge common shares to be issued pursuant to the merger agreement will be determined at the effective time based on the exchange ratio, the number of shares of Spectra Energy common stock outstanding at such time and the number of Spectra Energy stock options, phantom units, performance stock units and other equity-based awards. Based on the number of shares of Spectra Energy common stock outstanding as of [●], and the number of Enbridge common shares outstanding as of [●], immediately after completion of the merger, former Spectra Energy stockholders would own approximately [●]% of the outstanding Enbridge common shares.

Based on the closing price of Enbridge common shares on the NYSE on September 2, 2016, the last full trading day before the announcement of the merger agreement, the per share value of Spectra Energy common stock implied by the merger consideration was $40.33. Based on the closing price of Enbridge common shares on the NYSE on [●], the most recent practicable date prior to the date of this proxy statement/prospectus, the per share value of Spectra Energy common stock implied by the merger consideration was $[●]. The implied value of the merger consideration will fluctuate, however, as the market price of Enbridge common shares fluctuates, because the merger consideration that is payable per share of Spectra Energy common stock is a fixed fraction of an Enbridge common share. As a result, the value of the merger consideration that Spectra Energy stockholders will receive upon the completion of the merger could be greater than, less than or the same as the value of the merger consideration on the date of this proxy statement/prospectus or at the time of the special meeting. Accordingly, you are encouraged to obtain current stock price quotations for Spectra Energy common stock and Enbridge common shares before deciding how to vote with respect to the approval of the merger agreement. Spectra Energy common stock trades on the NYSE under the ticker symbol “SE” and Enbridge common shares

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trade on the NYSE and the TSX under the ticker symbol “ENB.” The price of Enbridge common shares on the NYSE is reported in U.S. dollars, while the price of Enbridge common shares on the TSX is reported in Canadian dollars.

Background of the Merger

Each of the Spectra Energy board of directors and the Enbridge board of directors, each with their respective senior management, and with the assistance of their respective financial and legal advisors, from time to time have separately and independently reviewed and considered various potential strategic opportunities and alternatives in light of industry, regulatory and economic trends and developments.

As part of these reviews, both Spectra Energy and Enbridge have evaluated potential transactions to advance their respective strategic objectives of enhancing stockholder value, supporting dividend growth and better serving customers and employees. In furtherance of these objectives, in recent years, Spectra Energy senior management and Enbridge senior management have from time to time met with various industry executives, including each other, to discuss possible strategic transactions and have discussed sporadically with each other the idea of a possible business combination between the two companies. Enbridge’s senior management has considered or discussed the possibility of a business combination transaction between Enbridge and Spectra Energy periodically for at least the last 18 months. During this period, Enbridge’s senior management has continued to monitor and evaluate Spectra Energy and since November 2015, has provided periodic updates to the Enbridge board of directors, including presenting to the board on the possibility of a business combination transaction with Spectra Energy at Enbridge’s regularly scheduled board meetings in November and December 2015, as well as at the board meeting held in February 2016. Gov. James J. Blanchard disclosed that his law firm does work for Spectra Energy and he has participated in representing Spectra Energy. As a result of this conflict, Gov. Blanchard did not participate in these discussions or in any future meetings or discussions relating to a possible transaction with Spectra Energy.

On May 10 and 11, 2016, the Enbridge board of directors held a regularly scheduled meeting, which was also attended by certain of Enbridge’s senior management. During the meeting, the Enbridge board of directors and members of senior management reviewed the possibility of a business combination transaction between Enbridge and Spectra Energy, including the strong strategic fit, long term growth platform, short and long term financial benefits, cultural fit and view of the strategic strengths of Spectra Energy’s asset base. The Enbridge board of directors determined that Enbridge senior management should continue to analyze a potential business combination transaction with Spectra Energy and initiate discussions with Spectra Energy’s senior management about such a transaction.

On May 20, 2016, Mr. Al Monaco, the Chief Executive Officer of Enbridge, called Mr. Gregory L. Ebel, the Chairman and Chief Executive Officer of Spectra Energy, to inform Mr. Ebel that the Enbridge board of directors recently had discussed the possibility of combining Enbridge with Spectra Energy and the board’s view, which Mr. Monaco shared, that it was an appropriate time for both companies to consider a possible transaction. During the call, Mr. Ebel and Mr. Monaco discussed the strategic rationale for a possible transaction and agreed that their respective senior management teams would coordinate to schedule a meeting during the first week of June, at which Enbridge’s senior management would present preliminary parameters under which a possible transaction might occur. During the conversation, Mr. Ebel informed Mr. Monaco that the strategic rationale for a possible transaction was consistent with the discussions that the Spectra Energy board of directors also had on this topic from time to time. Following the call, Mr. Ebel informed the Spectra Energy directors of his discussion with Mr. Monaco and the upcoming meeting with Enbridge senior management.

On June 1, 2016, Mr. Monaco and Mr. Ebel, accompanied by each company’s Chief Financial Officer and Chief Development Officer, met in Denver, Colorado to further discuss a possible transaction. At the meeting, Enbridge senior management presented its view regarding the strategic rationale for a transaction between the two companies, including the potential synergies, value drivers and dividend payout assumptions for the

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combined company. Enbridge senior management also presented its preliminary proposal on the financial parameters of a possible transaction, which included a premium of approximately 10% to the NYSE trading price of Spectra Energy common stock, with approximately 90% of the consideration consisting of Enbridge common shares and the remainder of the consideration consisting of cash. Also during the meeting, Mr. Ebel and Mr. Monaco discussed governance matters for the combined company. Mr. Monaco indicated that Enbridge’s preliminary view was that Mr. Ebel would become non-executive Chairman of the board of directors of the combined company, Mr. Monaco would serve as the Chief Executive Officer of the combined company, that there would be proportionate director representation (based on approximate relative share ownership) on the board of the combined company and that the combined company’s management team would be selected with the objective of building the strongest possible management team. Mr. Ebel told Mr. Monaco that he would discuss Enbridge’s preliminary proposal and the strategic rationale for a potential transaction with the Spectra Energy board of directors. Following the meeting, Mr. Ebel informed the Spectra Energy board of directors that discussions with Enbridge were constructive, there appeared to be significant value that could be created by combining the two companies and he would provide a detailed update during the next Spectra Energy board meeting.

On June 13 and 14, 2016, the Spectra Energy board of directors held a regularly scheduled meeting, which was also attended on June 14 by Spectra Energy management and representatives of BMOCM and Wachtell, Lipton, Rosen & Katz (which we refer to as “Wachtell Lipton”), Spectra Energy’s outside counsel. During the meeting, Spectra Energy management and representatives of BMOCM provided a summary of the preliminary discussions between Spectra Energy and Enbridge senior management and the preliminary terms that Enbridge had proposed for a possible combination of the two companies, including the financial parameters of a possible transaction, the combined company’s potential dividend policy and the possible composition of the combined company’s board and management. Representatives of BMOCM reviewed Spectra Energy’s and Enbridge’s recent stock performance and discussed preliminary financial matters regarding the proposed transaction, including with respect to each company on a standalone and combined basis. Also at this meeting, representatives of Wachtell Lipton reviewed with the Spectra Energy directors their fiduciary duties in connection with considering a possible business combination involving the two companies. Following discussion regarding these topics, the consensus of the Spectra Energy board of directors was that management and Spectra Energy’s advisors should continue to engage in discussions with representatives of Enbridge regarding a possible business combination and should report to the board with updates regarding these discussions.

On June 16, 2016, Mr. Ebel informed Mr. Monaco that the Spectra Energy board of directors had authorized further discussions regarding a possible combination of Spectra Energy and Enbridge. Mr. Ebel informed Mr. Monaco that the Spectra Energy board was of the view that the premium and stock/cash consideration mix for Spectra Energy stockholders, dividend growth commitments and the governance structure of the combined company were important open points requiring further discussion.

On June 17, 2016, Spectra Energy and Enbridge entered into a confidentiality agreement, which included reciprocal standstill restrictions. Each of Spectra Energy and Enbridge subsequently provided the other party and certain of their respective representatives with due diligence information, including with respect to the long term growth prospects of each company and the specific opportunities that underpinned these prospects, assumptions related to the potential synergies available in a business combination transaction between Enbridge and Spectra Energy and the potential credit profile of the combined company. For the remainder of June and throughout July and August, representatives of Spectra Energy and Enbridge engaged in mutual due diligence investigations on these and other topics, which included meetings, conference calls and review of materials in electronic data rooms.

On June 28 and 29, 2016, the Enbridge board of directors held a regularly scheduled meeting, which was also attended by certain of Enbridge’s senior management. Mr. Monaco updated the Enbridge board of directors on the initial discussions with Spectra Energy senior management and the strategic rationale for the transaction, including Spectra Energy’s competitive position and long term growth outlook, the dividend growth assumptions

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for the combined company and the positive impact on access to equity capital and share price. Enbridge management also discussed the potential credit rating impact of the proposed transaction. Enbridge management then discussed the initial results of their due diligence review of Spectra Energy and potential next steps. The Enbridge board of directors and members of management present agreed that Mr. Monaco and other senior management should continue to explore a potential business combination with representatives of Spectra Energy and conduct further due diligence investigations. The Enbridge board of directors directed management to provide an update on these matters at the next board meeting.

On June 30, 2016, Mr. Monaco called Mr. Ebel and advised him that the Enbridge board of directors supported the strategic rationale for combining Spectra Energy and Enbridge. Mr. Monaco also indicated that the Enbridge board of directors was scheduled to meet again at the end of July, at which time he wished to update the Enbridge board on various transaction matters, including rating agency and regulatory considerations.

Between June 30, 2016 and July 29, 2016, the respective Spectra Energy and Enbridge management teams and advisors continued to have meetings and conference calls regarding due diligence, regulatory and other matters. On July 21, 2016, Mr. Monaco called Mr. Ebel to discuss the upcoming meeting of the Enbridge board of directors on July 26 and 27, 2016 and reaffirmed Enbridge’s continued interest in assessing a combination of the two companies.

On July 26 and 27, 2016, the Enbridge board of directors held a regularly scheduled meeting, which was also attended by certain of Enbridge’s senior management. During the meeting, Mr. Monaco updated the Enbridge board of directors on his conversations with Mr. Ebel regarding a possible transaction and Spectra Energy’s willingness to explore a potential combination of the two companies. During the meeting, the Enbridge board, with the assistance of Credit Suisse Securities (Canada), Inc., which we refer to as “Credit Suisse”, one of Enbridge’s financial advisors, reviewed and discussed financial aspects of a possible business combination transaction between Enbridge and Spectra Energy. The Enbridge board of directors and members of management present then discussed the terms and timing of a possible transaction, including the form of consideration, premium, regulatory approvals, deal protection mechanisms, governance and tax matters. The Enbridge board of directors authorized Mr. Monaco and management to continue discussions with representatives of Spectra Energy to assess the viability of the combination and if it could be achieved on acceptable terms. The board further authorized Mr. Monaco to provide a written non-binding proposal to Mr. Ebel detailing Enbridge’s proposed terms for a merger with Spectra Energy.

On July 28, 2016, Mr. Monaco called Mr. Ebel to confirm that, consistent with prior discussions, the Enbridge board of directors viewed the combination of the two companies favorably, subject to due diligence and acceptable terms being reached by the parties. Mr. Ebel communicated to Mr. Monaco that he and the Spectra Energy board of directors shared the same favorable view, and that the premium and cash/stock consideration mix for Spectra Energy stockholders, dividend growth commitments and governance structure of the combined company remained open issues that needed to be resolved by the parties.

On July 29, 2016, the Spectra Energy board of directors held a special meeting, which was also attended by Spectra Energy management and representatives of BMOCM and Wachtell Lipton. During the meeting, Mr. Ebel updated the Spectra Energy board of directors about his conversations with Mr. Monaco regarding a possible transaction and Enbridge’s continued interest in combining the two companies. Mr. Ebel also informed the directors that Enbridge indicated that it would submit to Spectra Energy a written non-binding proposal detailing its proposed terms for a possible business combination. Also at the meeting, members of Spectra Energy management provided an overview of Enbridge’s business and corporate structure and the potential credit rating impact of the proposed transaction. Representatives of BMOCM provided a capital markets and industry update, reviewed Spectra Energy’s and Enbridge’s recent stock performance and discussed certain updated preliminary financial matters regarding a proposed transaction. Following discussion regarding these topics, the Spectra Energy board of directors indicated its support for management and advisors to continue to engage in discussions with representatives of Enbridge and report back to the board with updates regarding these discussions.

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Following the completion of the board meeting on July 29, 2016, Mr. Ebel called Mr. Monaco to reiterate that the premium and cash/stock consideration mix for Spectra Energy stockholders, anticipated dividend growth and governance structure of the combined company remained open issues that needed to be resolved by the parties.

Later in the day on July 29, 2016, Enbridge delivered a non-binding proposal letter to Spectra Energy, in which Enbridge proposed a merger with Spectra Energy. The letter, which was provided to the Spectra Energy directors on the same day, indicated that, further to the discussions which had occurred between the parties, the combined company would have a 12-member board, with the board Chairman and Chief Executive Officer roles to be split as previously discussed by the parties (with Mr. Ebel becoming the non-executive Chairman of the board of directors of the combined company and Mr. Monaco continuing to serve as the Chief Executive Officer of the combined company), the transaction consideration would consist primarily of stock with a low premium and the combined company would continue to have a major presence in Houston, Texas. The letter also indicated that Enbridge’s review of the proposed transaction suggested that the combined company was expected to be able to deliver annual dividend growth of 10% well into the next decade, while maintaining a conservative payout ratio.

On August 4, 2016, Mr. Monaco and Mr. Ebel discussed the proposed terms contained in Enbridge’s proposal letter and Mr. Ebel indicated that, among other things, the premium for Spectra Energy stockholders needed to exceed 10% in order for the transaction to be considered favorably by the Spectra Energy board of directors.

On August 5, 2016, the respective management teams of Spectra Energy and Enbridge, including the Chief Executive Officers of each company met, and with the assistance of representatives of Spectra Energy’s financial advisors, BMOCM and Citi, and Enbridge’s financial advisors, Credit Suisse and RBC Dominion Securities Inc., which we refer to as “RBC”, discussed possible transaction terms and certain financial matters, due diligence and value drivers for the combined company, including long term growth prospects and potential synergies. During this meeting, the Spectra Energy management team and the Enbridge management team discussed, among other things, the premium for the proposed transaction, the consideration mix for Spectra Energy stockholders, the size and composition of the combined company’s board, the role and tenure of the chairman of the board of directors of the combined company and matters regarding closing certainty, including the scope of each party’s covenants to obtain regulatory approvals. Spectra Energy management communicated to Enbridge management that, in addition to the resolution of the matters described above, a commitment to dividend growth of at least 10% per year as previously discussed was important to Spectra Energy’s willingness to pursue the proposed transaction.

On August 9, 2016, finance teams from Spectra Energy and Enbridge met to discuss various matters, including preparing for possible rating agency presentations, which were scheduled to occur in late August.

On August 15, 2016, the Spectra Energy board of directors held a special meeting, which was also attended by Spectra Energy management and representatives of BMOCM, Citi and Wachtell Lipton. During the meeting, Mr. Ebel and other members of Spectra Energy management discussed with the directors the outstanding transaction terms that Spectra Energy and Enbridge had been negotiating, including the premium and cash/stock consideration mix for Spectra Energy stockholders, dividend growth commitments, regulatory approvals, funding of interim operations, termination fees, board composition and tenure of the chairman of the board of directors of the combined company. Mr. Ebel and other members of management also discussed with the directors the results of the due diligence examination that had been undertaken to date, particularly regarding each company’s growth projects. Also during the meeting, representatives of BMOCM and Citi discussed potential timelines relating to the proposed transaction. Representatives of Wachtell Lipton reviewed with the Spectra Energy directors their fiduciary duties in connection with considering a possible business combination between the two companies. Following discussion regarding these topics, the Spectra Energy board of directors instructed management and advisors to continue to engage in negotiations with representatives of Enbridge regarding a possible business combination to achieve the best possible terms for the board’s review and report to the board with updates regarding these negotiations.

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On August 19, 2016, Sullivan & Cromwell LLP (which we refer to as “Sullivan & Cromwell”), Enbridge’s outside U.S. counsel, sent a draft merger agreement to Wachtell Lipton. The draft merger agreement provided for, among other things, a part cash and part stock transaction, generally reciprocal obligations and rights with respect to the ability of each party to change its board recommendation, generally reciprocal termination rights and termination fee triggers, a termination fee of 4% of the transaction’s equity value payable by either party in specified circumstances, expense reimbursement if the other party’s shareholders voted against the transaction, a prohibition on each party’s ability to terminate the merger agreement in order to enter into a superior proposal prior to the completion of the stockholder meetings relating to the transaction, the extent of Enbridge’s obligations in connection with obtaining regulatory approvals, an appraisal rights closing condition and a 12-person combined company board, comprised of four Spectra Energy designees (including Spectra Energy’s Chief Executive Officer who would become non-executive Chairman of the board of directors of the combined company), and eight Enbridge designees (including Enbridge’s Chief Executive Officer who would continue to serve as the Chief Executive Officer of the combined company).

Between August 19, 2016 and August 27, 2016, the respective Spectra Energy and Enbridge management teams and advisors engaged in discussions about, among other matters, the terms of the draft merger agreement.

On August 22, 2016, the Enbridge board of directors held a telephonic meeting that was also attended by certain members of senior management, representatives of Sullivan & Cromwell, McCarthy Tétrault LLP (which we refer to as “McCarthy Tétrault”), Enbridge’s Canadian counsel, Credit Suisse and RBC. During the meeting, Mr. Monaco and members of senior management updated the Enbridge board of directors on the discussions that had occurred between the Enbridge and Spectra Energy management teams. Representatives of Enbridge’s outside legal counsel reviewed with the directors their fiduciary duties in connection with considering a possible business combination with Spectra Energy and certain process issues that should be considered. Representatives of Credit Suisse and RBC each also reviewed and discussed with the Enbridge board the recent stock performance of Enbridge and Spectra Energy and the potential market reaction to an announcement of a business combination transaction with Spectra Energy. The Enbridge board of directors and members of senior management present discussed long term growth prospects, dividend growth commitments, estimated annual cost synergies that could be derived in connection with the transaction, the proposed mix of consideration, consisting mostly of Enbridge common shares, and the potential impact of the proposed transaction on Enbridge’s credit ratings. Also at this meeting, Enbridge’s directors, senior management and representatives of Enbridge’s advisors discussed preliminary terms of the merger, including deal protection, regulatory approvals, governance of the combined company, certain interim operating covenants, transition planning and integration, and closing conditions. Following discussion on these topics, the Enbridge board of directors directed Enbridge’s senior management and advisors to continue to engage in negotiations with representatives of Spectra Energy regarding the terms of a possible business combination transaction.

On August 23, 2016, the Spectra Energy board of directors held a regularly scheduled meeting, which was also attended by Spectra Energy management and representatives of BMOCM, Citi and Wachtell Lipton. During the meeting, Spectra Energy management updated the Spectra Energy directors on the discussions that had occurred between the respective Spectra Energy and Enbridge management teams and discussed with the directors the outstanding transaction terms that the respective Spectra Energy and Enbridge management teams and advisors had been negotiating, including the premium and cash/stock consideration mix for Spectra Energy stockholders, certain tax matters, dividend growth commitments, regulatory approvals, closing conditions, interim operations considerations and board composition and other governance matters. Spectra Energy management also provided an update on and discussed with the directors the estimated potential synergies that could result from the proposed transaction and discussed the results of the due diligence examination that had been completed as of that time. Also during the meeting, representatives of BMOCM and Citi reviewed Spectra Energy’s and Enbridge’s recent stock performance and discussed updated preliminary financial matters regarding the proposed transaction, including with respect to each company on a standalone and combined basis, as well as certain credit rating agency considerations. Representatives of Wachtell Lipton reviewed with the Spectra Energy directors their fiduciary duties in connection with considering a possible business combination between the two

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companies. Following discussion regarding these topics, the Spectra Energy board of directors provided direction with respect to outstanding matters and requested management and advisors to continue to engage in negotiations with representatives of Enbridge and report to the board with updates regarding the progress of these negotiations.

On August 25 and August 26, 2016, the respective senior management of Enbridge and Spectra Energy, including Mr. Monaco and Mr. Ebel and each company’s Chief Financial Officer, participated in meetings with credit rating agencies, during which they discussed the proposed transaction, pro forma corporate, financial and governance structure and strengths of the combined company.

Between August 27, 2016 and September 5, 2016, Wachtell Lipton and Sullivan & Cromwell, along with Goodmans LLP, Spectra Energy’s Canadian counsel, and McCarthy Tétrault, exchanged multiple revised drafts of the merger agreement reflecting various discussions and the respective parties’ positions on open items, including the cash/stock consideration mix for Spectra Energy stockholders, tax-related matters, regulatory efforts requirements, conditionality, termination provisions, termination fee triggers and amounts, and governance provisions. Also during this period, the Spectra Energy and Enbridge management teams continued to negotiate the respective parties’ positions on these items and worked on preparing additional information for the rating agencies.

On August 28, 2016, the Spectra Energy board of directors held a special meeting, which was also attended by Spectra Energy management and representatives of BMOCM, Citi and Wachtell Lipton, and included Mr. Monaco for the opening segment of the meeting. Mr. Monaco presented to the Spectra Energy directors, among other matters, his vision for the combined company and responded to questions from Spectra Energy’s directors. After Mr. Monaco departed the meeting, Spectra Energy management and Spectra Energy’s legal and financial advisors updated the Spectra Energy directors on the discussions that had occurred between Spectra Energy and Enbridge management teams and discussed with the directors the outstanding transaction terms that they and the advisors had been negotiating. Also during the meeting, representatives of BMOCM and Citi reviewed Spectra Energy’s and Enbridge’s recent stock performance and discussed updated preliminary financial matters regarding the proposed transaction. Representatives of Wachtell Lipton reviewed with the Spectra Energy directors their fiduciary duties in connection with considering a possible business combination between the two companies and provided an overview of the terms of the draft merger agreement. In addition, Spectra Energy management and representatives of Wachtell Lipton discussed with the Spectra Energy directors employee compensation and benefits related matters. Following discussion regarding these topics, the Spectra Energy board of directors provided direction with respect to outstanding matters and requested management and advisors to continue negotiations and report to the board with updates regarding the progress of these negotiations.

Between August 28, 2016 and September 1, 2016, the respective Spectra Energy and Enbridge management and advisors continued to negotiate the remaining open transaction terms, particularly the exchange ratio that would determine the number of Enbridge common shares Spectra Energy stockholders would receive for their Spectra Energy common stock, the cash/stock consideration mix for Spectra Energy stockholders, termination provisions and termination fee triggers, certain tax matters and governance terms.

On August 29, 2016, the Enbridge board of directors held a telephonic meeting that was also attended by certain of Enbridge’s senior management and representatives of Sullivan & Cromwell, Credit Suisse and RBC. During the meeting, members of senior management of Enbridge updated the Enbridge board of directors on the negotiations between the Enbridge and Spectra Energy management teams and their advisors, including outstanding transaction terms and open issues, which included premium and mix, regulatory approvals, board composition and other governance matters. Enbridge’s senior management also discussed Enbridge’s potential credit ratings in connection with a business combination transaction with Spectra Energy and planned discussions with the rating agencies. Enbridge senior management also discussed with Enbridge’s directors whether, given Spectra Energy’s preference for more stock as part of the merger consideration, Enbridge should consider proposing consideration consisting entirely of Enbridge common shares. Enbridge’s senior management then

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updated and discussed with the Enbridge board of directors that due diligence on Spectra Energy had effectively been completed and an updated financial analysis would be presented at the next board meeting. Following discussion regarding these topics, the Enbridge board of directors directed management and Enbridge’s advisors to continue to engage in negotiations with representatives of Spectra Energy and to report to the board with updates regarding the progress of these negotiations and feedback from the ratings agencies.

On September 1, 2016, representatives of Enbridge sent a revised proposal to Spectra Energy, which provided for an exchange ratio of 0.870 of an Enbridge common share plus $3.82 in cash for each share of Spectra Energy common stock, which represented an approximately 7% premium to the closing price of Spectra Energy common stock on August 31, 2016. The proposal indicated that the combined cash/stock consideration was equivalent to an exchange ratio of 0.966 of an Enbridge common share for each share of Spectra Energy common stock if it were an all-stock transaction. The proposal also provided for a reciprocal termination fee of 3.85% based on the respective equity values of Spectra Energy and Enbridge, but did not include proposals regarding the size and composition of the combined company’s board and committees. The proposal also indicated that it was subject to rating agency confirmation of Enbridge’s current credit ratings.

On September 2, 2016, following discussions with Spectra Energy management, representatives of Enbridge sent a revised proposal to Spectra Energy, which provided for an exchange ratio of 0.966 in a stock-for-stock merger, which represented a 9.53% premium to the closing price of Spectra Energy common stock on September 2, 2016. The proposal also provided for a reciprocal termination fee of 3.85% based on the respective equity values of Spectra Energy and Enbridge, but did not address the size and composition of the combined company’s board and committees. The proposal also indicated that it was subject to rating agency confirmation of Enbridge’s current credit ratings, which discussions remained ongoing.

On September 3, 2016, the Spectra Energy board of directors held a special meeting with Spectra Energy management and representatives of BMOCM, Citi and Wachtell Lipton to receive an update on and review the proposed terms and conditions of a possible transaction with Enbridge, which was now proposed to be an all-stock merger. Spectra Energy management provided an update on the negotiations and Enbridge’s September 2, 2016 revised proposal as well as additional information on due diligence and potential synergies. Representatives of BMOCM and Citi discussed with the Spectra Energy board of directors updated preliminary financial matters regarding the proposed transaction. Representatives of Wachtell Lipton reviewed with the Spectra Energy directors their fiduciary duties in connection with considering the merger and reviewed in detail the terms of the draft merger agreement, including the terms that remained subject to further negotiation. Following discussion regarding these topics, the Spectra Energy board of directors reiterated its support for the transaction with Enbridge and instructed management to continue negotiations with Enbridge, including to seek an increase of the exchange ratio and improvement of certain of the other terms discussed at this meeting, with another meeting of the Spectra Energy board of directors to be scheduled after more clarity was received from the rating agencies.

Following the September 3, 2016 Spectra Energy board meeting, Spectra Energy management sent a revised proposal to Enbridge, which provided for, among other things, an increase in the exchange ratio to 0.988 based on the closing price of Enbridge common shares on the NYSE on September 2, 2016, with an adjustment if the transaction was not to be announced by the opening of business on September 6, 2016 and the price of Enbridge common shares was to decline relative to the price of Spectra Energy common stock, a reduction in the termination fees to 3.5% of the respective equity values of Spectra Energy and Enbridge, Spectra Energy having five designees on the combined company’s 13-person board and proportional board committee representation.

On September 4, 2016, the Enbridge board of directors held a special meeting which was also attended by Enbridge management and representatives of Sullivan & Cromwell, McCarthy Tétrault, Credit Suisse and RBC. Enbridge management provided the Enbridge board of directors with an update on the most recent transaction negotiations. Representatives of Enbridge’s outside legal counsel reviewed with the Enbridge directors their fiduciary duties in connection with considering the merger and reviewed the terms of the draft merger agreement, including the terms that remained subject to further negotiation. The Enbridge board of directors, with the

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assistance of representatives of Credit Suisse and RBC then reviewed and discussed financial aspects of a possible business combination transaction between Enbridge and Spectra Energy. Members of Enbridge management reviewed with the directors the completed due diligence investigations on Spectra Energy and the feedback of the credit rating agencies on Enbridge’s credit ratings upon the closing of the proposed transaction, as well as anticipated synergies and transaction costs of the proposed transaction. Following the discussion regarding these topics, Enbridge’s board of directors reiterated its support for the transaction with Spectra Energy and instructed Enbridge’s senior management and advisors to continue negotiations with Spectra Energy.

During the early morning hours on September 5, 2016, representatives of Sullivan & Cromwell sent a revised draft merger agreement to representatives of Wachtell Lipton, which provided for, among other things, a 0.980 exchange ratio, 3.5% termination fees based on the respective equity values of Spectra Energy and Enbridge and a 13-person combined company board, with five Spectra Energy designees. Thereafter, the parties and their respective legal advisors continued to negotiate the exchange ratio and finalize the remaining open terms of the draft merger agreement.

By the afternoon of September 5, 2016, the parties agreed to, among other things, submit for consideration by their respective boards of directors the terms of a transaction based on an exchange ratio of 0.984, which represented an implied value per share of Spectra Energy common stock of $40.33, based on the closing price of Enbridge common shares on the NYSE on September 2, 2016 (the last trading day prior to announcement of the merger), and an approximate 11.5% premium to the closing price of Spectra Energy common stock on the same date. In addition, the parties agreed to termination fees equal to 3.5% of the respective equity values of Spectra Energy and Enbridge, a 13-person combined company board, with five Spectra Energy designees, proportional representation of the Spectra Energy designees on each board committee and Mr. Ebel becoming the non-executive Chairman of the board of directors of the combined company. Enbridge management also received and shared with Spectra Energy management favorable feedback from the credit rating agencies regarding their view of Enbridge’s credit rating upon the closing of the proposed transaction.

On September 5, 2016, the Enbridge board of directors held a special meeting with Mr. Ebel, who spoke with the Enbridge board of directors regarding Spectra Energy and his continued enthusiasm for the potential combination of the two companies, discussed Spectra Energy’s strategic approach, and shared his perspective on the benefits of the combination for all investors. Once Mr. Ebel departed, Enbridge management and representatives of Sullivan & Cromwell, McCarthy Tétrault, Credit Suisse and RBC joined the meeting. Enbridge management provided a review of the completed due diligence investigations on Spectra Energy and an update on the most recent transaction negotiations, including the proposed 0.984 exchange ratio. Representatives of Enbridge’s external legal counsel reviewed with the Enbridge directors their fiduciary duties in connection with considering the merger and then reviewed the principal terms of the merger agreement. The Enbridge board of directors, with the assistance of representatives of Credit Suisse and RBC then reviewed and discussed the financial aspects of the proposed transaction between Enbridge and Spectra Energy. Representatives of management discussed the possible effect of the transaction on Enbridge non-shareholder constituencies, including creditors, employees and communities. Based on the discussions and deliberations at the September 4, 2016 and September 5, 2016 board meetings and after considering the terms of the merger agreement and the other factors described under “ The Merger Proposal — Enbridge ’ s Reasons for the Merger ” the Enbridge board of directors (i) determined that the merger was in the best interests of Enbridge and Merger Sub, authorized and approved the merger agreement and resolved to recommend approval of the issuance of Enbridge common shares in connection with the merger and the by-law amendment to Enbridge shareholders and (ii) directed that the issuance of the Enbridge common shares to be issued in connection with the merger and the by-law amendment be submitted to the Enbridge stockholders for their approval. The Enbridge board of directors then authorized Enbridge’s senior management to finalize and execute the merger agreement on substantially the terms reviewed at the board meeting.

During the evening of September 5, 2016, the Spectra Energy board of directors held a special meeting at which Spectra Energy management and representatives of BMOCM, Citi and Wachtell Lipton were present. Spectra Energy management provided an update on the most recent transaction negotiations, including the

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proposed 0.984 exchange ratio, and management’s view that, based on positions taken by Enbridge, this was the maximum exchange ratio that Enbridge would be willing to agree to in the merger. Also at this meeting, representatives of BMOCM and Citi separately reviewed with the Spectra Energy board of directors the respective financial analyses of BMOCM and Citi of the exchange ratio and rendered BMOCM’s and Citi’s respective oral opinions, confirmed by delivery of written opinions, dated September 5, 2016, to the Spectra Energy board of directors to the effect that, as of such date and based on and subject to various assumptions made, procedures followed, matters considered and limitations and qualifications on the review undertaken, the exchange ratio provided for pursuant to the merger agreement was fair, from a financial point of view, to holders of Spectra Energy common stock. Also at the meeting, representatives of Wachtell Lipton reviewed the draft merger agreement and provided an update on the proposed terms and conditions. Based on the discussions and deliberations at the September 3, 2016 and September 5, 2016 board meetings and after receiving Spectra Energy management’s favorable recommendation of the merger, the Spectra Energy board of directors unanimously determined that the merger agreement and the transactions contemplated by the merger agreement were fair to, and in the best interests of, Spectra Energy and its stockholders, approved and declared advisable the merger agreement and the transactions contemplated by the merger agreement, authorized management to execute the merger agreement on behalf of Spectra Energy, directed that the merger agreement be submitted to a vote at a meeting of Spectra Energy stockholders, resolved to recommend that Spectra Energy stockholders vote to adopt the merger agreement and approved and authorized certain related matters.

Following the approvals by each of the Spectra Energy board of directors and Enbridge board of directors, Spectra Energy and Enbridge finalized and executed the merger agreement.

On the morning of September 6, 2016, Spectra Energy and Enbridge issued a joint press release announcing the merger agreement.

Board of Directors and Management of Enbridge after the Merger

Board of Directors

Pursuant to the merger agreement, as of the effective time, the Enbridge board of directors will consist of a total of 13 directors, comprised of eight directors designated by Enbridge and five directors designated by Spectra Energy. Mr. Al Monaco will serve as President and Chief Executive Officer of the combined company and Mr. Gregory L. Ebel will serve as non-executive Chairman of the board of directors of the combined company.

The remaining members of the Enbridge board of directors following completion of the merger have not yet been determined. Pursuant to the merger agreement, at least five business days prior to the closing date, Spectra Energy will designate five directors (including Mr. Ebel) from the Spectra Energy board of directors to be appointed to the Enbridge board of directors, which we refer to as the “Spectra Energy designees.” If any of the Spectra Energy designees was not a director of Spectra Energy as of the date of the merger agreement, Enbridge will have the right to consent to such designation (such consent not to be unreasonably withheld, conditioned or delayed). For more information, see the section entitled “ The Merger Agreement—Effects of the Merger—Enbridge Governance and Other Matters .”

Biographical information for Mr. Monaco is incorporated herein by reference from Enbridge’s Notice of 2016 Annual Meeting and Management Information Circular, filed with the SEC on Form 6-K on March 31, 2016. Biographical information for Mr. Ebel is incorporated herein by reference from Spectra Energy’s Definitive Proxy Statement for its 2016 Annual Meeting of Shareholders, filed with the SEC on March 16, 2016.

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