REGISTRATION RIGHTS AGREEMENT

Exhibit 4.3

EXECUTION COPY

REGISTRATION RIGHTS AGREEMENT

THIS REGISTRATION RIGHTS AGREEMENT (this " Agreement ") is made and entered into as of December 11, 2006 among ACADIA REALTY TRUST, a Maryland real estate investment trust (the " Company ") and LEHMAN BROTHERS INC. and Merrill Lynch, Pierce, Fenner & Smith Incorporated, as the initial purchasers (the " Initial Purchasers ") named in Schedule A to the Purchase Agreement (as defined below).

This Agreement is made pursuant to the Purchase Agreement dated December 5, 2006 (the " Purchase Agreement ") among the Company and the Initial Purchasers, which provides for, among other things, the sale of 3.75% Convertible Notes Due 2026 (the "Notes") of the Company to the Initial Purchasers.

In order to induce the Initial Purchasers to enter into the Purchase Agreement, the Company has agreed to provide to the Initial Purchasers and their respective direct and indirect transferees the registration rights set forth in this Agreement.

In consideration of the foregoing, the parties hereto agree as follows:

1.             Definitions. Capitalized terms used herein without definition shall have the respective meanings ascribed to them in the Purchase Agreement. As used in this Agreement, the following capitalized defined terms shall have the following meanings:

"Additional Interest" has the meaning set forth in Section 2(e) hereof .

"Advice " has the meaning set forth in the last paragraph of Section 3 hereof.

" Affiliate " has the same meaning as given to that term in Rule 405 under the Securities Act or any successor rule thereunder.

" Automatic Shelf Registration Statement " means a registration statement filed by a Well-Known Seasoned Issuer, which shall become effective upon filing thereof pursuant to General Instruction I.D of Form S-3.

" Business Day " means any day other than a Saturday, a Sunday, or a day on which banking institutions in New York, New York are authorized or required by law or executive order to remain closed.

" Common Shares " means common shares of beneficial interest of the Company, par value $0.001 per share, issuable upon conversion of the Notes.

" Company " has the meaning set forth in the preamble to this Agreement and also includes the Company’s successors and permitted assigns.

" Effective Date " means the date the initial Shelf Registration Statement becomes effective or, in the case of designation of an Automatic Shelf Registration Statement as the Shelf Registration Statement, the date a Prospectus is first made available thereunder for use by the Holders.

" Effectiveness Deadline " means (i) for purposes of Section 2(a)(i) hereof, the 210th day following the Issue Date, (ii) for purposes of the filing of any post-effective amendment pursuant to Section 2(a)(iii) hereof, the 30th day after the obligation to make such filing arises, (iii) for purposes of the filing of any Shelf Registration Statement pursuant to Section 2(a)(iii) hereof, the 60th day after the obligation to make such filing arises, and (iv) for purposes of any filing made pursuant to Section 2(a)(iv) hereof, the tenth Business Day after the obligation to make such filing arises.

" Effectiveness Period " has the meaning set forth in Section 2(a)(iv) hereof.

" Exchange Act " means the Securities Exchange Act of 1934, as amended from time to time.

" Filing Deadline " means (i) for purposes of Section 2(a)(i) hereof, the 120th day following the Issue Date, (ii) for purposes of Section 2(a)(iii) hereof, the tenth Business Day after the date of receipt by the Company of the information specified therein (or, if a Suspension Period is then in effect or initiated within five Business Days following the date of receipt of such information, the tenth Business Day following the end of such Suspension Period), and (iii) for purposes of Section 2(a)(iv) hereof, the tenth Business Day after the cessation of effectiveness of any Shelf Registration Statement (or, if a Suspension Period is then in effect or initiated within five Business Days following the date of receipt of such information, the tenth Business Day following the end of such Suspension Period).

" Holder " means each Initial Purchaser, for so long as such Initial Purchaser owns any Registrable Securities, and each of such Initial Purchaser’s respective successors, assigns and direct and indirect transferees who become registered owners of Registrable Securities.

" Indenture " means the Indenture dated as of December 11, 2006, as supplemented by the First Supplemental Indenture dated December 11, 2006, by and between the Company and the Trustee, pursuant to which the Notes are being issued, and in accordance with which Common Shares may be issued, as the same may be amended, supplemented, waived or otherwise modified from time to time in accordance with the terms thereof.

" Initial Purchasers " has the meaning set forth in the preamble to this Agreement.

" Inspectors " has the meaning set forth in Section 3(l) hereof.

" Issue Date " means December 11, 2006, being the date of original issuance of the Notes.

" Majority Holders " means the Holders collectively holding a majority of the aggregate principal amount of outstanding Notes or the number of outstanding Common Shares, as the context requires.

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" Notes " has the meaning set forth in the preamble to this Agreement.

" Person " means an individual, partnership, corporation, trust or unincorporated organization, limited liability corporation, or a government or agency or political subdivision thereof.

" Prospectus " means the prospectus included in a Shelf Registration Statement, including any preliminary prospectus, any issuer "free writing prospectus," as such term is defined in Rule 433 under the Securities Act, and any such prospectus as amended or supplemented by any prospectus supplement, including a prospectus supplement with respect to the terms of the offering of any portion of the Registrable Securities covered by a Shelf Registration Statement, and by all other amendments and supplements to a prospectus, including post-effective amendments, and, in each case, including all documents incorporated by reference therein.

" Purchase Agreement " has the meaning set forth in the preamble to this Agreement.

" Questionnaire " has the meaning set forth in Section 2(a)(ii) hereof.

" Records " has the meaning set forth in Section 3(l) hereof.

" Registrable Securities " means the Notes and the Common Shares; provided, however , that (i) the Notes shall cease to be Registrable Securities upon the earlier of (1) a Shelf Registration Statement with respect to such Notes for the resale thereof having been declared effective under the Securities Act and such Notes having been disposed of pursuant to such Shelf Registration Statement, (2) such Notes having become eligible to be sold without restriction as contemplated by Rule 144(k) under the Securities Act by a Person who is not an Affiliate of the Company, or (3) such Notes having ceased to be outstanding, and (ii) the Common Shares shall cease to be Registrable Securities upon the earlier of (1) a Shelf Registration Statement with respect to such Common Shares for the resale thereof having been declared effective under the Securities Act and such Common Shares having been disposed of pursuant to such Shelf Registration Statement, (2) such Common Shares having become eligible to be sold without restriction as contemplated by Rule 144(k) under the Securities Act by a Person who is not an Affiliate of the Company, or (3) such Common Shares having ceased to be outstanding.

" Registration Expenses " means any and all expenses incident to performance of or compliance by the Company with this Agreement, including without limitation: (i) all SEC or National Association of Securities Dealers, Inc. (the " NASD ") registration and filing fees, not including the fees and expenses of any "qualified independent underwriter" (and its counsel), (ii) all fees and expenses incurred in connection with compliance with state securities or blue sky laws (not including fees and disbursements of counsel for underwriters or Holders in connection with blue sky qualification of any of the Registrable Securities) and compliance with the rules of the NASD, (iii) all expenses of any Persons in preparing or assisting in preparing, word processing, printing and distributing any Shelf Registration Statement, any Prospectus and any amendments or supplements thereto, and in preparing or assisting in preparing, printing and distributing any underwriting agreements, securities sales agreements and other documents

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relating to the performance of and compliance with this Agreement, (iv) all rating agency fees, (v) the fees and disbursements of counsel for the Company and of the independent certified public accountants of the Company, including the expenses of any "comfort letters" required by or incident to the performance of and compliance with this Agreement, and (vi) the reasonable fees and expenses of any special experts retained by the Company in connection with the Shelf Registration Statement.

" SEC " means the Securities and Exchange Commission.

" Securities " means the Notes and the Common Shares.

" Securities Act " means the Securities Act of 1933, as amended from time to time.

" Shelf Registration " means a registration effected pursuant to Section 2(a) hereof.

" Shelf Registration Statement " means a "shelf" registration statement of the Company pursuant to the provisions of Section 2(a) hereof which covers all of the Registrable Securities on Form S-3 or, if not then available to the Company, on another appropriate form under Rule 415 under the Securities Act, or any similar rule that may be adopted by the SEC, and all amendments and supplements to such registration statement, including post-effective amendments, in each case including the Prospectus contained therein, all exhibits thereto and all documents incorporated by reference therein.

" Suspension Period " has the meaning set forth in Section 2(a)(iv).

" Trustee " means the trustee with respect to the Securities under the Indenture.

" Well-Known Seasoned Issuer " has the meaning set forth in Rule 405 under the Securities Act.

(i)           The Company shall file or cause to be filed (or otherwise designate an existing Automatic Shelf Registration Statement previously filed with the SEC as) a Shelf Registration Statement providing for the resale by the Holders of all of the Registrable Securities, as promptly as reasonably practicable but in any event on or prior to the Filing Deadline. If the Shelf Registration Statement is not an Automatic Shelf Registration Statement, the Company shall use its reasonable best efforts to have such Shelf Registration Statement declared effective by the SEC as promptly as reasonably practicable after filing thereof, but in any event on or prior to the Effectiveness Deadline. If the Shelf Registration Statement is an Automatic Shelf Registration Statement, the Company shall use its reasonable best efforts to prepare and file a supplement to the Prospectus to cover resales of the Registrable Securities by the Holders as promptly as reasonably practicable after filing thereof, but in any event on or prior to the Effectiveness Deadline.

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(ii)         Notwithstanding any other provision hereof, no Holder of Registrable Securities shall be entitled to include any of its Registrable Securities in any Shelf Registration Statement pursuant to this Agreement unless and until such Holder agrees in writing to be bound by all of the provisions of this Agreement applicable to such Holder and the Holder furnishes to the Company a fully completed notice and questionnaire in the form attached as Annex A to the Offering Memorandum (the " Questionnaire ") and such other information in writing as the Company may reasonably request in writing for use in connection with the Shelf Registration Statement or Prospectus included therein and in any application to be filed with or under state securities laws. The Company shall issue a press release through a reputable national newswire service (and post it on its website or disseminate it through other appropriate public medium) regarding its filing (or intention to designate an Automatic Shelf Registration Statement as) of the Shelf Registration Statement and of the anticipated Effective Date thereof. In order to be named as a selling security holder in the Prospectus at the time it is first made available for use, each Holder must furnish the completed Questionnaire and such other information that the Company may reasonably request in writing, if any, to the Company in writing no later than the tenth Business Day prior to the anticipated Effective Date as announced in the press release. Each Holder as to which any Shelf Registration is being effected agrees to furnish to the Company from time to time all information with respect to such Holder necessary to make the information previously furnished to the Company by such Holder not materially misleading.

(iii)         From and after the Effective Date, upon receipt of a completed Questionnaire and such other information that the Company may reasonably request in writing, if any, the Company will use its reasonable best efforts to file as promptly as reasonably practicable but in any event on or prior to the Filing Deadline either (i) if then permitted by the Securities Act or the rules and regulations thereunder (or then-current SEC interpretations thereof), a supplement to the Prospectus naming such Holder as a selling security holder and containing such other information as necessary to permit such Holder to deliver the Prospectus to purchasers of the Holder’s Securities, or (ii) if it is not then permitted under the Securities Act or the rules and regulations thereunder (or then-current SEC interpretations thereof) to name such Holder as a selling security holder in a supplement to the Prospectus, a post-effective amendment to the Shelf Registration Statement or an additional Shelf Registration Statement as necessary for such Holder to be named as a selling security holder in the Prospectus contained therein to permit such Holder to deliver the Prospectus to purchasers of the Holder’s Registrable Securities (subject, in the case of either clause (i) or (ii), to the Company’s right to suspend use of the Shelf Registration Statement as described in Section 2(a)(iv) hereof). If a post-effective amendment or additional Shelf Registration Statement is required to be filed, the Company shall use its reasonable best efforts to have such post-effective amendment or additional Shelf Registration Statement declared effective by the SEC as promptly as practicable after filing thereof, but in any event on or prior to the Effectiveness Deadline. The Company shall not be required to file more than three supplements to the Prospectus, two post-effective amendments or one additional Shelf Registration Statements in any fiscal quarter for all such Holders.

(iv)         The Company agrees to use its reasonable best efforts to keep the Shelf Registration Statement continuously effective and the Prospectus usable for resales until there are no Registrable Securities outstanding (the " Effectiveness Period "); provided, however , that for 30 days or less (whether or not consecutive) in any three-month

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period, and for 90 days or less (whether or not consecutive) in any 12-month period, the Company shall be permitted, by giving written notice to the Holders of Registrable Securities, to suspend sales thereof if the Shelf Registration Statement is no longer effective or usable for resales due to circumstances relating to pending developments, public filings with the SEC and similar events, or because the Prospectus contains an untrue statement of a material fact or omits to state a material fact required to be stated therein or necessary in order to make statements therein not misleading (any period of suspension hereunder, a " Suspension Period "). If any Shelf Registration Statement ceases to be effective or usable for resales by Holders for any reason (other than by reason of any such Holder’s failure to provide a Questionnaire, in which case the provisions of Section 2(a)(ii) or 2(a)(iii) hereof shall apply) at any time during the Effectiveness Period, the Company shall, subject to the proviso contained in the immediately preceding sentence, use its reasonable best efforts to promptly cause such Shelf Registration Statement to become effective under the Securities Act, and in any event shall, within ten Business Days of such cessation of effectiveness or usability, (i) file with the SEC one or more supplements to the Prospectus, post-effective amendments or reports under the Exchange Act in a manner reasonably expected to obtain the withdrawal of any order suspending the effectiveness of such Shelf Registration Statement, or (ii) file with the SEC an additional Shelf Registration Statement. If a post-effective amendment or an additional Shelf Registration Statement is filed, the Company shall use its reasonable best efforts to (A) cause such post-effective amendment or Shelf Registration Statement to become effective under the Securities Act as promptly as reasonably practicable after such filing, but in no event later than the applicable Effectiveness Deadline, and (B) keep such post-effective amendment or Shelf Registration Statement continuously effective until the end of the Effectiveness Period.

(v)          If the Shelf Registration Statement is not an Automatic Shelf Registration Statement, the Company shall not permit any securities other than (i) the Company’s issued and outstanding securities currently possessing incidental or so-called "piggy-back" registration rights and (ii) the Registrable Securities to be included in the Shelf Registration. The Company will provide to each Holder named therein a reasonable number of copies of the Prospectus which is a part of the Shelf Registration Statement, notify each such Holder of the Effective Date and take such other actions as are required to permit unrestricted resales of the Registrable Securities by such Holder. The Company further agrees to supplement or amend the Shelf Registration Statement or supplement the Prospectus if and as required by the rules, regulations or instructions applicable to the registration form used by the Company for such Shelf Registration Statement or by the Securities Act or by any other rules and regulations thereunder for shelf registrations, and the Company agrees to furnish to the Holders of Registrable Securities copies of any such supplement or amendment as promptly as reasonably practicable after its being used or filed with the SEC.

(b)           Listing. The Company shall use its reasonable best efforts to maintain the approval of the Common Shares for listing on the New York Stock Exchange during the Effectiveness Period.

(c)           Expenses. The Company shall pay all Registration Expenses in connection with any Shelf Registration Statement filed pursuant to Section 2(a) hereof. Each Holder shall pay all expenses of its counsel, underwriting discounts and commissions and

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transfer taxes, if any, relating to the sale or disposition of such Holder’s Registrable Securities pursuant to the Shelf Registration Statement.

(d)           Effective Shelf Registration Statement. If, after the Effective Date the offering of Registrable Securities pursuant to a Shelf Registration Statement is interfered with by any stop order, injunction or other order or requirement of the SEC or any other governmental agency or court, such Shelf Registration Statement will be deemed not to have been effective during the period of such interference, until the offering of Registrable Securities pursuant to such Shelf Registration Statement may legally resume.

(i)           a Shelf Registration Statement is not filed with the SEC or designated as such by the Company on or prior to the Filing Deadline pursuant to Section 2(a)(i), then additional interest (" Additional Interest ") shall accrue on the principal amount of the Securities at a rate equal to 0.25% per year for the first 90-day period from the day following such Filing Deadline, and thereafter at a rate per year of 0.50% of the principal amount of the Securities;

(ii)          (x) a Shelf Registration Statement is not declared effective by the SEC, or (y) if the Company shall have designated a previously filed and effective Automatic Shelf Registration Statement as the Shelf Registration Statement for purposes of this Agreement, the Company shall not have filed a supplement to the Prospectus to cover resales of the Registrable Securities by the Holders, in the case of either (x) or (y), on or prior to the Effectiveness Deadline pursuant to Section 2(a)(i), then Additional Interest shall accrue on the principal amount of the Securities at a rate equal to 0.25% per year for the first 90-day period from the day following such Effectiveness Deadline, and thereafter at a rate per year of 0.50% of the principal amount of the Securities;

(iii)        following the Effective Date, (A) the Company fails to make any filing required pursuant to Section 2(a)(iii) hereof prior to the Filing Deadline applicable thereto, or (B) in the event such filing is a post-effective amendment or additional Shelf Registration Statement, such post-effective amendment or Shelf Registration Statement fails to become effective on or prior to the Effectiveness Deadline applicable thereto, then Additional Interest shall accrue on the principal amount of the Securities at a rate equal to 0.25% per year for the first 90-day period from the day following such Filing Deadline or Effectiveness Deadline, as applicable, and thereafter at a rate per year of 0.50% of the principal amount of the Securities;

(iv)         following the Effective Date, a Shelf Registration Statement ceases to be effective (without being succeeded immediately by an additional Shelf Registration Statement that is filed and immediately becomes effective) or usable for the offer and sale of the Registrable Securities, other than in connection with (A) a Suspension Period or (B) as a result of a requirement to file a post-effective amendment or supplement to the Prospectus to make changes to the information regarding selling security holders or the plan of distribution provided for therein, and the Company does not cure the lapse of effectiveness or usability within ten Business Days (or, if a Suspension Period is then in effect, within ten

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Business Days following the expiration of such Suspension Period), then Additional Interest shall accrue on the principal amount of the Securities at a rate equal to 0.25% per year for the first 90-day period from the day following such tenth Business Day, and thereafter at a rate per year of 0.50% of the principal amount of the Securities;

(v)          any Suspension Period or Periods exceed 30 days in any three-month period or 90 days in any 12-month period, then, commencing with the 31st day in such three-month period or the 91st day in such 12-month period, as the case may be, then Additional Interest shall accrue on the principal amount of the Securities at a rate equal to 0.25% per year for the first 90-day period from the day following the 31st or 91st day, as the case may be, and thereafter at a rate per year of 0.50% of the principal amount of the Securities; or

(vi)         the Company fails to name as a selling security holder any Holder that had complied timely with its obligations hereunder in a manner to entitle such Holder to be so named in (A) any Shelf Registration Statement at the time it first becomes effective or (B) any Prospectus at the later of time of filing thereof or the time the Shelf Registration Statement of which the Prospectus forms a part becomes effective, then Additional Interest will accrue on the principal amount of Securities held by such Holder at a rate equal to 0.25% per year for the first 90-day period from the day following the effective date of such Shelf Registration Statement or the time of filing of such Prospectus, as the case may be, and thereafter at a rate per year of 0.50% of the principal amount of the Securities held by such Holder;

provided, however , that in no event shall Additional Interest accrue at a rate per year exceeding 0.50% of the principal amount of the Securities; and provided, further , that Additional Interest on the principal amount of the Securities as a result thereof shall cease to accrue:

(1)          upon the filing or designation of a Shelf Registration Statement (in the case of clause (i) above);

(2)          upon the Effective Date (in the case of clause (ii) above);

(3)          upon the filing of a supplement to the Prospectus, a post-effective amendment or an additional Shelf Registration Statement (in the case of clause (iii)(A) above) or upon the Effective Date (in the case of clause (iii)(B) above);

(4)          upon such time as the Shelf Registration Statement which had ceased to remain effective or usable for resales again becomes effective and usable for resales (in the case of clause (iv) above);

(5)          upon such time as the Shelf Registration Statement which had ceased to remain effective or usable for resales again becomes effective and usable for resales (in the case of clause (v) above); or

(6)          upon the time such Holder is permitted to sell its Registrable Securities pursuant to any Shelf Registration Statement and Prospectus in accordance with applicable law (in the case of clause (vi) above).

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Any amounts of Additional Interest due pursuant to Section 2(e) will be payable semi-annually in arrears in cash on the next succeeding interest payment date to Holders entitled to receive such Additional Interest on the relevant record dates for the payment of interest.

Notwithstanding any provision in this Agreement, in no event shall Additional Interest accrue to holders of Common Shares issued upon conversion of the Notes. If any Note ceases to be outstanding during any period for which Additional Interest are accruing, the Company will prorate the Additional Interest payable with respect to such Note. Additional Interest shall represent the sole entitlement of the Holders to money damages relating to the failure of the Company to file or otherwise designate a Shelf Registration Statement with the SEC on or prior to the Filing Deadline.

(f)            Specific Enforcement. Without limiting the remedies available to the Holders, the Company acknowledges that any failure by it to comply with its obligations under Section 2(a) hereof may result in m