Property

Location

Retail Properties

Carmel Country Plaza

Carmel Mountain Plaza ⁽¹⁾

South Bay Marketplace ⁽¹⁾

Rancho Carmel Plaza

Lomas Santa Fe Plaza

Solana Beach Towne Centre

Del Monte Center ⁽¹⁾

The Shops at Kalakaua

Waikele Center

Alamo Quarry ⁽¹⁾

Subtotal/Weighted Average Retail Portfolio

Office Properties

Torrey Reserve Campus

Solana Beach Corporate Centre

Valencia Corporate Center

160 King Street ⁽²⁾

The Landmark at One Market ⁽³⁾

Subtotal/Weighted Average Office Portfolio

Total/Weighted Average Retail and Office Portfolio

The net rentable square feet for each of our retail properties and the retail portion of our mixed-use property is the sum of (1) the square footages of existing leases, plus (2) for available space, the field verified square footage. The net rentable square feet for each of our office properties is the sum of (1) the square footages of existing leases, plus (2) for available space, management’s estimate of net rentable square feet based, in part, on past leases. The net rentable square feet included in such office leases is generally determined consistently with the Building Owners and Managers Association, or BOMA, 1996 measurement guidelines.

Percentage leased for each of our retail and office properties is calculated as (1) square footage under commenced leases as of June 30, 2010, divided by (2) net rentable square feet, expressed as a percentage, while percentage leased for our multifamily properties is calculated as (1) total units rented as of June 30, 2010, divided by (2) total units available, expressed as a percentage.

Annualized base rent is calculated by multiplying (1) base rental payments (defined as cash base rents (before abatements)) for the month ended June 30, 2010, by (2) 12. Annualized base rent per leased square foot is calculated by dividing (1) annualized base rent, by (2) square footage under commenced leases as of June 30, 2010. In the case of triple net or modified gross leases, annualized base rent does not include tenant reimbursements for real estate taxes, insurance, common area or other operating expenses. Total abatements for leases in effect as of June 30, 2010 for (1) our retail and office portfolio and (2) our mixed-use portfolio will equal approximately $237,000 and zero, respectively, for the 12 months ending June 30, 2011. Total abatements for leases in effect as of June 30, 2010 for our multifamily portfolio equaled approximately $897,636 for the 12 months ended June 30, 2010.

Average net effective annual base rent per leased square foot represents (1) the contractual base rent for leases in place as of June 30, 2010, calculated on a straight-line basis to amortize free rent periods and abatements, but without regard to tenant improvement allowances and leasing commissions, divided by (2) square footage under commenced leases as of June 30, 2010.

Units represent the total number of units available for sale/rent at June 30, 2010.

Average occupancy represents the percentage of available units that were sold during the 12-month period ended June 30, 2010, and is calculated by dividing (1) the number of units sold by (2) the product of the total number of units and the total number of days in the period. Average daily rate represents the average rate paid for the units sold, and is calculated by dividing (1) the total room revenue (i.e., excluding food and beverage revenues or other hotel operations revenues such as telephone, parking and other guest services) for the 12-month period ended June 30, 2010, by (2) the number of units sold. Revenue per available room, or RevPAR, represents the total unit revenue per total available units for the 12-month period ended June 30, 2010 and is calculated by multiplying average occupancy by the average daily rate. RevPAR does not include food and beverage revenues or other hotel operations revenues such as telephone, parking and other guest services.

Average monthly base rent per leased unit represents the average monthly base rent per leased units for the 12-month period ended June 30, 2010.

consolidate the ownership of our portfolio under our company and our operating partnership;

cause us to succeed to the property management business;

facilitate this offering;

enable us to raise necessary capital to repay existing indebtedness related to certain properties in our portfolio;

enable us to qualify as a REIT for federal income tax purposes commencing with the taxable year ending December 31, 2010;

defer the recognition of taxable gain by certain prior investors; and

enable prior investors to obtain liquidity for their investments.

We were formed as a Maryland corporation on July 16, 2010.

American Assets Trust, L.P., our operating partnership, was formed as a Maryland limited partnership on July 16, 2010.

We will sell             shares of our common stock in this offering and an additional             shares if the underwriters exercise their overallotment option in full, and we will contribute the net proceeds from this offering to our operating partnership in exchange for            common units (or            common units if the underwriters exercise their overallotment option in full).

We will succeed to the property management business as a result of the contribution by American Assets, Inc. of the assets and liabilities associated with the property management business to its wholly owned subsidiary, American Assets Trust Management, LLC, and the subsequent contribution of its interest in that entity to our operating partnership in exchange for            common units.

We and our operating partnership will consolidate the ownership of our portfolio of properties by acquiring the entities that directly or indirectly own such properties or by acquiring interests in such entities through a series of forward and reverse merger transactions and contributions pursuant to merger agreements and contribution agreements each dated September 13, 2010, with such entities or the owners thereof. The value of the consideration to be paid to each of the owners of such entities in the formation transactions will be determined according to the terms of such merger agreements and contribution agreements.

Prior investors in the merged and contributed entities (including Messrs. Rady, Chamberlain and Barton and their respective affiliates) will receive as consideration for such mergers and contributions              shares of our common stock,             common units, or in the case of non-accredited investors in such entities, $             in cash in accordance with the terms of the relevant merger and/or contribution agreements. The aggregate value of common stock and common units to be paid to prior investors in such entities at the mid-point of the range of prices shown on the cover of this prospectus is $            . This value will increase or decrease if our common stock is priced above or below the mid-point of the range of prices shown on the cover of this prospectus. Investors who are not “accredited investors,” as defined under Regulation D of the Securities Act, will receive cash consideration rather than shares of our common stock or common units to ensure that the issuance of common stock and/or common units to accredited investors in the formation transactions can be effected in reliance upon an exemption from registration provided by Section 4(2) and Regulation D of the Securities Act.

The Rady Trust has entered into a representation, warranty and indemnity agreement, pursuant to which it has made certain representations and warranties to us regarding the entities and assets being acquired in the formation transactions and agreed to indemnify us and our operating partnership for breaches of such representations and warranties for one year after the completion of this offering and the formation transactions. For purposes of satisfying any indemnification claims, the Rady Trust will deposit into escrow             shares of our common stock and             common units with an aggregate value equal to ten percent of the consideration payable to the Rady Trust and its affiliates in the formation transactions. The Rady Trust has no obligation to increase the amount of common stock or common units in the escrow in the event the trading price of our common stock declines below the initial public offering price. Any and all amounts remaining in the escrow one year from the closing of the formation transactions will be distributed to the Rady Trust to the extent that indemnity claims have not been made against such amounts. This indemnification is subject to a one-time aggregate deductible equal to one percent of the consideration payable to the Rady Trust and its affiliates in the formation transactions and a cap equal to the value of the consideration deposited in the escrow. Other than the Rady Trust, none of the prior investors or the entities that we are acquiring in the formation transactions will provide us with any indemnification.

The current management team of American Assets, Inc. will become our senior management team, and the current real estate professionals employed by American Assets, Inc. will become our employees.

Our operating partnership intends to use a portion of the net proceeds of this offering to repay approximately $341.4 million of outstanding indebtedness, including applicable prepayment costs,

exit fees and defeasance costs of $24.3 million. As a result of the foregoing uses of proceeds, we expect to have approximately $879.9 million of total debt outstanding upon completion of this offering and the formation transactions. We determined the loans to be repaid based upon our determination of which would be economically prudent to repay, taking into account the maturity dates, interest rates and prepayment costs, exit fees and defeasance costs associated with the various outstanding loans.

In conjunction with this offering, we anticipate entering into an agreement for a $             million revolving credit facility. We expect to use this facility to fund future capital expenditures related to lease-up, acquisitions and for general corporate purposes.

In connection with the foregoing transactions, we expect to adopt a cash and equity-based incentive award plan and other incentive plans for our directors, officers, employees and consultants. We expect that an aggregate of             shares of our common stock will be available for issuance under awards granted pursuant to our 2010 Equity Incentive Award Plan. See “Executive Compensation—Equity Incentive Award Plan.”

Mr. Rady, our Executive Chairman, and his affiliates, including the Rady Trust, will receive             shares of our common stock and             common units in connection with the formation transactions, with an aggregate value of approximately $             million. As a result, Mr. Rady and his affiliates will own approximately     % of our company on a fully diluted basis, or     % if the underwriters’ overallotment option is exercised in full. In addition, Mr. Rady and his affiliates will receive an aggregate of approximately $         million in cash, as discussed in the bullets below.

In connection with the formation transactions, we will repay in cash from the proceeds of this offering (1) approximately $4.9 million in notes payable to certain of the prior investors in Del Monte Center and (2) approximately $350,000 in notes payable to certain prior investors in Torrey Reserve Campus. In their capacity as direct or indirect owners of the entities that own Del Monte Center and the Torrey Reserve Campus, Mr. Rady and his affiliates will receive approximately $3.8 million and $30,000, respectively, of these amounts.

In connection with the formation transactions, Mr. Rady and his affiliates will receive an estimated $             million of cash as a result of the payment of the excess net working capital over target net working capital in each ownership entity in which Mr. Rady and his affiliates are prior investors.

Mr. Chamberlain, our Chief Executive Officer and director, and his affiliates will receive             shares of our common stock and             common units in connection with the formation transactions, with an aggregate value of approximately $             million. As a result, Mr. Chamberlain and his affiliates will own approximately     % of our company on a fully diluted basis, or     % if the underwriters’ overallotment option is exercised in full.

In connection with the formation transactions, Mr. Chamberlain and his affiliates will receive an estimated $             million of cash as the result of the payment of the excess net working capital over target net working capital in each ownership entity in which Mr. Chamberlain and his affiliates are prior investors.

Mr. Barton, our Chief Financial Officer, and his affiliates will receive             shares of our common stock and             common units in connection with the formation transactions, with an aggregate value of approximately $             million. As a result, Mr. Barton and his affiliates will own approximately     % of our company on a fully diluted basis, or     % if the underwriters’ overallotment option is exercised in full.

In connection with the formation transactions, Mr. Barton and his affiliates will receive an estimated $             million of cash as the result of the payment of the excess net working capital over target net working capital in each ownership entity in which Mr. Barton and his affiliates are prior investors.

The Rady Trust and certain other affiliates of Mr. Rady are guarantors of approximately $75.4 million of indebtedness, in the aggregate, which will be repaid with proceeds from this offering and, as a result, the Rady Trust and these other affiliates of Mr. Rady will be released from these guarantee obligations. In addition, the Rady Trust and certain other affiliates of Mr. Rady are guarantors of approximately $879.9 million of indebtedness, in the aggregate, that will be assumed by us upon completion of this offering. In connection with this assumption, we will seek to have the Rady Trust and such other affiliates of Mr. Rady released from such guarantees and to have our operating partnership assume any such guarantee obligations as replacement guarantor. To the extent lenders do not consent to the release of the Rady Trust and/or such other affiliates of Mr. Rady, and the Rady Trust and such other affiliates remain guarantors on assumed indebtedness following the IPO, our operating partnership will enter into a reimbursement agreement with the Rady Trust and such affiliates, pursuant to which our operating partnership will be obligated to reimburse the Rady Trust and such other affiliates of Mr. Rady for any amounts paid by them under guarantees with respect to the assumed indebtedness.

We will enter into a tax protection agreement with certain limited partners of our operating partnership, including Mr. Rady and his affiliates and an affiliate of Mr. Chamberlain, pursuant to which we agree to indemnify such limited partners against adverse tax consequences in connection with: (1) our sale of Carmel Country Plaza, Carmel Mountain Plaza, Del Monte Center, Loma Palisades, Lomas Santa Fe Plaza, Waikele Center or the ICW Plaza portion of Torrey Reserve in a taxable transaction until the seventh anniversary of the closing of the formation transactions; and (2) our failure to provide certain limited partners the opportunity to guarantee certain debt of our operating partnership during such period, or following such period, our failure to use commercially reasonable efforts to provide such opportunities; provided that, subject to certain exceptions and limitations, such indemnification rights will terminate for any such protected partner that sells, exchanges or otherwise disposes of more than 50% of his or her common units. Mr. Rady and his affiliates and an affiliate of Mr. Chamberlain will have the opportunity to guarantee up to $             million and $             million, respectively, of our outstanding indebtedness, pursuant to the tax protection agreement. See “Structure and Formation of Our Company—Benefits of the Formation Transactions to Related Parties.”

In connection with the completion of this offering, we will enter into a registration rights agreement with the various persons receiving shares of our common stock and/or common units in the formation transactions, including Mr. Rady his affiliates, immediate family members and related trusts and certain of our other directors and executive officers and their affiliates pursuant, to which, commencing not later than 14 months after the date of this offering, we will be obligated to file one or more registration statements for our common stock. We will agree to pay all of the expenses relating to such securities registrations. See “Shares Eligible for Future Sale—Registration Rights.”

We may enter into employment agreements with certain of our executive officers that would become effective as of the closing of this offering, which would be expected to provide for salary,

bonus and other benefits, including accelerated equity vesting upon a change in control and severance upon a termination of employment under certain circumstances. The material terms of the agreements with our named executive officers are described under “Executive Compensation—Employment Agreements” and “Executive Compensation—Compensation Tables—Narrative Disclosure to Summary Compensation Table.”

We intend to enter into indemnification agreements with directors and executive officers at the closing of this offering, providing for procedures for indemnification by us to the fullest extent permitted by law and advancements by us of certain expenses and costs relating to claims, suits or proceedings arising from their service to us or, at our request, service to other entities, as officers or directors.

We intend to adopt our 2010 Equity Incentive Award Plan, under which we may grant cash or equity incentive awards to our directors, officers, employees and consultants. See “Executive Compensation—Equity Incentive Award Plan.”