WARRANT AGREEMENT

Exhibit 10.2

WARRANT AGREEMENT

dated as of [    ], 2008

between

BOSTON PRIVATE FINANCIAL HOLDINGS, INC.

and

[            ]

as WARRANT AGENT

THIS WARRANT AGREEMENT, dated as of [    ], 2008 (this “Agreement”), between Boston Private Financial Holdings, Inc., a Massachusetts corporation (the “Company”) and [            ], as Warrant Agent (the “Warrant Agent”);

WHEREAS, the Company has entered into an Investment Agreement, dated as of July 22, 2008 (the “Investment Agreement”; capitalized terms being used herein as therein defined), between the Company and BP Holdco, L.P., a Delaware limited partnership (“Purchaser”);

WHEREAS, pursuant to the Investment Agreement, the Company proposes to sell to Purchaser and Purchaser proposes to purchase Warrants representing the right to purchase shares of Common Stock, which Warrants shall be governed by this Agreement and evidenced by certificates issued pursuant to this Agreement (such warrant certificates and other warrant certificates issued pursuant to this Agreement being herein called the “Warrant Certificates”); and

WHEREAS, the Company desires the Warrant Agent to act on behalf of the Company in connection with the issuance, exchange, exercise and replacement of the Warrant Certificates, and in this Agreement wishes to set forth, among other things, the form and provisions of the Warrant Certificates and the terms and conditions on which they may be issued, exchanged, exercised and replaced.

NOW THEREFORE, in consideration of the premises and of the mutual agreements herein contained, the parties hereto agree as follows:

ARTICLE I

ISSUANCE OF WARRANTS AND EXECUTION

AND DELIVERY OF WARRANT CERTIFICATES

SECTION 1.1. Issuance of Warrants. Upon issuance, each Warrant Certificate shall evidence one or more Warrants. Each Warrant evidenced thereby shall represent the right, subject to the provisions contained herein and therein, to purchase the number of shares of Common Stock set forth in the Warrant Certificate.

SECTION 1.2. Execution and Delivery of Warrant Certificates. Each Warrant Certificate, whenever issued, shall be in registered form substantially in the form set forth in Exhibit A hereto, shall be dated and may have such letters, numbers, or other marks of identification or designation and such legends or endorsements printed, lithographed or engraved thereon as the officers of the Company executing the same may approve (execution thereof to be conclusive evidence of such approval) and as are not inconsistent with the provisions of this Agreement, or as may be required to comply with any law or with any rule or regulation made pursuant thereto or with any rule or regulation of any stock exchange on which the Warrants may be listed, or to conform to usage. The Warrant Certificates shall be executed on behalf of the Company by the Chairman of the Board, the President, any Vice Chairman, or any Vice President and by the Secretary or any Assistant Secretary. Such signatures may be manual or facsimile signatures of such authorized officers and may be imprinted or otherwise reproduced in the Warrant Certificates.

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No Warrant Certificates shall be valid for any purpose, and no Warrant evidenced thereby shall be exercisable, until such Warrant Certificate has been countersigned by the manual signature of the Warrant Agent. Such signature by the Warrant Agent upon any Warrant Certificate executed by the Company shall be conclusive evidence that the Warrant Certificate so countersigned has been duly issued hereunder.

In case any officer of the Company who shall have signed any of the Warrant Certificates either manually or by facsimile signature shall cease to be such officer before the Warrant Certificates so signed shall have been countersigned and delivered by the Warrant Agent, such Warrant Certificates may be countersigned and delivered notwithstanding that the person who signed such Warrant Certificates ceased to be such officer of the Company; and any Warrant Certificate may be signed on behalf of the Company by such persons as, at the actual date of the execution of such Warrant Certificate, shall be the proper officers of the Company, although at the date of the execution of this Agreement any such person was not such officer.

The term “Warrantholder” as used herein shall mean any person in whose name at the time any Warrant Certificate shall be registered upon the books to be maintained by the Warrant Agent for that purpose.

SECTION 1.3. Issuance of Warrant Certificates. The Warrant Agent shall, upon receipt of Warrant Certificates duly executed on behalf of the Company, countersign Warrant Certificates evidencing Warrants representing the right to purchase up to [            ] shares of Common Stock in the aggregate and shall deliver such Warrant Certificates to or upon the order of the Company. Subsequent to such issuance of the Warrant Certificates, the Warrant Agent shall countersign a Warrant Certificate only if the Warrant Certificate is issued in exchange or substitution for one or more previously countersigned Warrant Certificates or in connection with their transfer, as hereinafter provided.

ARTICLE II

EXERCISE PRICE, DURATION

AND EXERCISE OF WARRANTS

SECTION 2.1. Exercise Price. (a) The exercise price (the “Exercise Price”) of each Warrant will be as set forth in the form of Warrant Certificate set forth as Exhibit A, the terms of which shall be deemed incorporated herein by reference as if fully set forth herein.

SECTION 2.2. Duration and Exercise of Warrants. (a) Each Warrant may be exercised in whole at any time during the period specified in the form of Warrant Certificate set forth as Exhibit A. During such period, any whole number of Warrants may be exercised by providing certain information as set forth on the reverse side of the Warrant Certificate and by paying the Exercise Price for each Warrant exercised, to the Warrant Agent as set forth in the Warrant Certificate. The Warrant Agent shall deposit all funds received by it in payment of the Exercise Price in an account of the Company maintained with it and shall advise the Company

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by telephone at the end of each day on which a payment for the exercise of Warrants is received of the amount so deposited to its account. The Warrant Agent shall promptly confirm such telephone advice to the Company in writing.

(b) The Warrant Agent shall, from time to time, as promptly as practicable, advise the Company of (i) the number of Warrants exercised, (ii) the instructions of each Warrantholder with respect to delivery of the Common Stock to which such Warrantholder is entitled upon such exercise, (iii) delivery of Warrant Certificates evidencing the balance, if any, of the Warrants remaining after such exercise, and (iv) such other information as the Company shall reasonably require.

SECTION 2.3. Compliance with Governmental Requirements. Before taking any action that would cause an adjustment reducing the Exercise Price to be adjusted below the then par value of any of the shares of Common Stock issuable upon exercise of the Warrants, the Company will take any corporate action that may, in the opinion of its counsel, be necessary in order that the Company may validly and legally issue fully paid and nonassessable shares of such Common Stock at such adjusted Exercise Price.

The Company covenants that if any shares of Common Stock required to be reserved for purposes of exercise of Warrants require, under any federal or state law or rule or regulation of any national securities exchange, registration with or approval of any governmental authority, or listing on any national securities exchange before such shares may be issued upon exercise, the Company will in good faith and as expeditiously as possible endeavor to cause such shares to be duly registered, approved or listed on the relevant national securities exchange, as the case may be; provided, however, that in no event shall such shares of Common Stock be issued, and the Company is hereby authorized to suspend the exercise of all Warrants, for the period during which such registration, approval or listing is required but not in effect.

ARTICLE III

ADJUSTMENT OF EXERCISE PRICE AND SHARES OF

COMMON STOCK PURCHASABLE

SECTION 3.1. Adjustment of Exercise Price. The Exercise Price specified in Section 2.1, and the number of shares of Common Stock issuable upon such exercise shall be subject to adjustment from time to time as set forth in the form of Warrant Certificate set forth as Exhibit A.

SECTION 3.2. Statements on Warrants. The form of Warrant Certificate need not be changed because of any adjustment made pursuant to this Article III, and Warrant Certificates issued after such adjustment may state the same Exercise Price and the same number of shares of Common Stock as are stated in the Warrant Certificates initially issued pursuant to this Agreement. The Company, however, may at any time, in its sole discretion (which shall be conclusive), make any change in the form of Warrant Certificate that it may deem appropriate and that does not affect the substance thereof, and any Warrant Certificate thereafter issued or countersigned, whether in exchange or substitution for an outstanding Warrant Certificate or otherwise, may be in the form as so changed.

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ARTICLE IV

EXCHANGE AND TRANSFER OF WARRANT CERTIFICATES

SECTION 4.1. Exchange and Transfer of Warrant Certificates. Upon surrender in accordance with the terms set forth in the Warrant Certificate, and upon compliance with the terms set forth in such Warrant Certificate, and subject to the restrictions and limitations set forth in the Warrant Certificate, Warrant Certificates evidencing Warrants may be exchanged for Warrant Certificates in other denominations evidencing such Warrants or the transfer thereof may be registered in whole or in part; provided that such other Warrant Certificates evidence the same aggregate number of Warrants as the Warrant Certificates so surrendered. The Warrant Agent shall keep, at its corporate trust office, books in which, subject to such reasonable regulations as it may prescribe, it shall register Warrant Certificates and exchanges and transfers of outstanding Warrant Certificates. Whenever any Warrant Certificates are so surrendered for exchange or registration of transfer, an authorized officer of the Warrant Agent shall manually countersign and deliver to the person or persons entitled thereto a Warrant Certificate or Warrant Certificates duly authorized and executed by the Company, as so requested. All Warrant Certificates issued upon any exchange or registration of transfer of Warrant Certificates shall be the valid obligations of the Company, evidencing the same obligations, and entitled to the same benefits under this Agreement as the Warrant Certificate surrendered for such exchange or registration of transfer.

SECTION 4.2. Cancellation of Warrant Certificates. Any Warrant Certificates surrendered for exchange, registration of transfer or exercise of the Warrants evidenced thereby shall, if surrendered to the Company, be delivered to the Warrant Agent, and all Warrant Certificates surrendered or so delivered to the Warrant Agent shall be promptly canceled by the Warrant Agent and shall not be reissued and, except as expressly permitted by this Agreement, no Warrant Certificate shall be issued hereunder in exchange or in lieu thereof. The Warrant Agent shall deliver to the Company from time to time or otherwise dispose of canceled Warrant Certificates in a manner satisfactory to the Company.

ARTICLE V

CONCERNING THE WARRANT AGENT

SECTION 5.1. Warrant Agent. The Company hereby appoints [            ] as Warrant Agent of the Company in respect of the Warrants and the Warrant Certificates upon the terms and subject to the conditions herein set forth; and [            ] hereby accepts such appointment. The Warrant Agent shall have the powers and authority granted to and conferred upon it in the Warrant Certificates and herein and such further powers and authority to act on behalf of the Company as the Company may hereafter grant to or confer upon it. All of the terms and provisions with respect to such powers and authority contained in the Warrant Certificates are subject to and governed by the terms and provisions hereof.

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SECTION 5.2. Conditions of Warrant Agent’s Obligations. The Warrant Agent accepts its obligations herein set forth upon the terms and conditions hereof, including the following, to all of which the Company agrees and to all of which the rights hereunder of the Warrantholders from time to time shall be subject:

(a) Compensation and Indemnification. The Company agrees promptly to pay the Warrant Agent the compensation to be agreed upon with the Company for all services rendered by the Warrant Agent and to reimburse the Warrant Agent for reasonable out-of-pocket expenses (including reasonable counsel fees) incurred by the Warrant Agent without negligence, bad faith or breach of this Agreement on its part in connection with the services rendered hereunder by the Warrant Agent. The Company also agrees to indemnify the Warrant Agent for, and to hold it harmless against, any loss, liability or expense incurred without negligence or bad faith on the part of the Warrant Agent, arising out of or in connection with its acting as Warrant Agent hereunder, as well as the costs and expenses of defending against any claim of such liability.

(b) Agent for the Company. In acting under this Agreement and in connection with the Warrant Certificates, the Warrant Agent is acting solely as agent of the Company and does not assume any obligations or relationship of agency or trust for or with any of the Warrantholders or beneficial owners of Warrants.

(c) Counsel. The Warrant Agent may consult with counsel satisfactory to it, and the written advice of such counsel shall be full and complete authorization and protection in respect of any action taken, suffered or omitted by it hereunder in good faith and in accordance with the advice of such counsel.

(d) Documents. The Warrant Agent shall be protected and shall incur no liability for or in respect of any action taken or thing suffered by it in reliance upon any Warrant Certificate, notice, direction, consent, certificate, affidavit, statement or other paper or document reasonably believed by it to be genuine and to have been presented or signed by the proper parties.

(e) Certain Transactions. The Warrant Agent, and its officers, directors and employees, may become the owner of, or acquire any interest in, Warrants, with the same rights that it or they would have if it were not the Warrant Agent hereunder, and, to the extent permitted by applicable law, it or they may engage or be interested in any financial or other transaction with the Company and may act on, or as depositary, trustee or agent for, any committee or body of Warrantholders or other obligations of the Company as freely as if it were not the Warrant Agent hereunder.

(f) No Liability for Interest. Unless otherwise agreed with the Company, the Warrant Agent shall have no liability for interest on any monies at any time received by it pursuant to any of the provisions of this Agreement or of the Warrant Certificates.

(g) No Liability for Invalidity. The Warrant Agent shall have no liability with respect to any invalidity of this Agreement or any of the Warrant Certificates (except as to the Warrant Agent’s countersignature thereon).

(h) No Responsibility for Representations. The Warrant Agent shall not be responsible for any of the recitals or representations herein or in the Warrant Certificates (except as to the Warrant Agent’s countersignature thereon), all of which are made solely by the Company.

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(i) No Implied Obligations. The Warrant Agent shall be obligated to perform only such duties as are herein and in the Warrant Certificates specifically set forth and no implied duties or obligations shall be read into this Agreement or the Warrant Certificates against the Warrant Agent. The Warrant Agent shall not be under any obligation to take any action hereunder which may tend to involve it in any expense or liability, the payment of which within a reasonable time is not, in its reasonable opinion, assured to it. The Warrant Agent shall not be accountable or under any duty or responsibility for the use by the Company of any of the Warrant Certificates authenticated by the Warrant Agent and delivered by it to the Company pursuant to this Agreement or for the application by the Company of the proceeds of the Warrant Certificates. The Warrant Agent shall have no duty or responsibility in case of any default by the Company in the performance of its covenants or agreements contained herein or in the Warrant Certificates or in the case of the receipt of any written demand from a Warrantholder with respect to such default, including, without limiting the generality of the foregoing, any duty or responsibility to initiate or attempt to initiate any proceedings at law or otherwise or, except as provided in Section 6.2 hereof, to make any demand upon the Company.

SECTION 5.3. Resignation and Appointment of Successor. (a) The Company agrees, for the benefit of the Warrantholders, that there shall at all times be a Warrant Agent hereunder until all the Warrants have been exercised or are no longer exercisable.

(b) The Warrant Agent may at any time resign as such agent by giving written notice to the Company of such intention on its part, specifying the date on which its desired resignation shall become effective; provided that such date shall not be less than 90 days after the date on which such notice is given unless the Company otherwise agrees. The Warrant Agent hereunder may be removed at any time by the filing with it of an instrument in writing signed by or on behalf of the Company and specifying such removal and the date when it shall become effective. Such resignation or removal shall take effect upon the appointment by the Company, as hereinafter provided, of a successor warrant agent (which shall be a bank or trust company in good standing authorized under the laws of the jurisdiction of its organization to exercise corporate trust powers) and the acceptance of such appointment by such successor warrant agent. The obligation of the Company under Section 5.2(a) shall continue to the extent set forth therein notwithstanding the resignation or removal of the Warrant Agent.

(c) In case at any time the Warrant Agent shall resign, or shall be removed, or shall become incapable of acting, or shall be adjudged a bankrupt or insolvent, or shall commence a voluntary case under the federal bankruptcy laws, as now or hereafter constituted, or under any other applicable federal or state bankruptcy, insolvency or similar law or shall consent to the appointment of or taking possession by a receiver, custodian, liquidator, assignee, trustee, sequestrator (or other similar official) of the Warrant Agent or its property or affairs, or shall make an assignment for the benefit of creditors, or shall admit in writing its inability to pay its debts generally as they become due, or shall take corporate action in furtherance of any such action, or a decree or order for relief by a court having jurisdiction in the premises shall have been entered in respect of the Warrant Agent in an involuntary case under the federal bankruptcy

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laws, as now or hereafter constituted, or any other applicable federal or state bankruptcy, insolvency or similar law; or a decree or order by a court having jurisdiction in the premises shall have been entered for the appointment of a receiver, custodian, liquidator, assignee, trustee, sequestrator (or similar official) of the Warrant Agent or of its property or affairs, or any public officer shall take charge or control of the Warrant Agent or of its property or affairs for the purpose of rehabilitation, conservation, winding up or liquidation, a successor warrant agent, qualified as aforesaid, shall be appointed by the Company by an instrument in writing, filed with the successor warrant agent. Upon the appointment as aforesaid of a successor warrant agent and acceptance by the successor warrant agent of such appointment, the Warrant Agent shall cease to be warrant agent hereunder.

(d) Any successor warrant agent appointed hereunder shall execute, acknowledge and deliver to its predecessor and to the Company an instrument accepting such appointment hereunder, and thereupon such successor warrant agent, without any further act, deed or conveyance, shall become vested with all the authority, rights, powers, trusts, immunities, duties and obligations of such predecessor with like effect as if originally named warrant agent hereunder, and such predecessor, upon payment of its charges and disbursements then unpaid, shall thereupon become obligated to transfer, deliver and pay over, and such successor warrant agent shall be entitled to receive, all monies, securities and other property on deposit with or held by such predecessor, as warrant agent hereunder.

(e) Any corporation into which the Warrant Agent hereunder may be merged or converted or any corporation with which the Warrant Agent may be consolidated, or any corporation resulting from any merger, conversion or consolidation to which the Warrant Agent shall be a party, or any corporation to which the Warrant Agent shall be a party or any corporation to which substantially all the assets and business of the Warrant Agent, provided that it shall be qualified as aforesaid, shall be the successor warrant agent under this Agreement without the execution or filing of any paper or any further act on the part of any of the parties hereto.

ARTICLE VI

MISCELLANEOUS

SECTION 6.1. Amendment. (a) This Agreement may be amended by the parties hereto, without the consent of any Warrantholder, for the purpose of curing any ambiguity, or of curing, correcting or supplementing any defective provision contained herein, or making any other provisions with respect to matters or questions arising under this Agreement as the Company and the Warrant Agent may deem necessary or desirable; provided that such action shall not affect adversely the interests of the Warrantholders.

(b) The Company and the Warrant Agent may modify or amend this Agreement (by means of an agreement supplemental hereto or otherwise) with the consent of Warrantholders constituting not less than a majority in number of the then outstanding Warrants affected by such modification or amendment; provided, however, that no such modification or amendment that changes the Exercise Price of the Warrants, reduces the amount receivable upon exercise, cancellation or expiration of the Warrants other than in accordance with the antidilution

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provisions or other similar adjustment provisions included in the terms of the Warrants, shortens the period of time during which the Warrants may be exercised, or otherwise materially and adversely affects the exercise rights of the affected Warrantholders or reduces the percentage of the number of outstanding Warrants, the consent of whose Warrantholders is required for modification or amendment of this Agreement, may be made without the consent of each Warrantholder affected thereby.

SECTION 6.2. Notices and Demands to the Company and Warrant Agent. If the Warrant Agent shall receive any notice or demand addressed to the Company by a Warrantholder pursuant to the provisions of the Warrant Certificates, the Warrant Agent shall promptly forward such notice or demand to the Company.

SECTION 6.3. Addresses. Any communication from the Company to the Warrant Agent with respect to this Agreement shall be addressed to [                    ], c/o Boston Private Financial Holdings, Inc., Ten Post Office Square, Boston, MA, 02109 and any communication from the Warrant Agent to the Company with respect to this Agreement shall be addressed to Boston Private Financial Holdings, Inc., Ten Post Office Square, Boston, MA, 02109, Attention: Margaret W. Chambers, Esq. (or such other address as shall be specified in writing by the Warrant Agent or by the Company).

SECTION 6.4. Applicable Law. This Agreement, and each Warrant Certificate issued hereunder and of the respective terms and provisions thereof, will be governed by and construed in accordance with the laws of the State of New York applicable to contracts made and to be performed entirely within such State (except to the extent that mandatory provisions of Massachusetts law are applicable). The parties hereby irrevocably and unconditionally consent to submit to the exclusive jurisdiction of the state and federal courts located in the Borough of Manhattan, State of New York for any actions, suits or proceedings arising out of or relating to this Agreement and the transactions contemplated hereby.

SECTION 6.5. Obtaining of Governmental Approvals. The Company will from time to time take all action which may be necessary to obtain and keep effective any and all permits, consents and approvals of governmental agencies and authorities and securities acts filings under United States federal and state laws, which may be or become requisite in connection with the issuance, sale, transfer, and delivery of the Common Stock issued upon exercise of the Warrants, the issuance, sale, transfer and delivery of the Warrants or upon the expiration of the period during which the Warrants are exercisable.

SECTION 6.6. Persons Having Rights under this Agreement. Nothing in this Agreement shall give to any person other than the Company, the Warrant Agent and the Warrantholders any right, remedy or claim under or by reason of this Agreement.

SECTION 6.7. Headings. The descriptive headings of the several Articles and Sections of this Agreement are inserted for convenience only and shall not control or affect the meaning or construction of any of the provisions hereof.

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SECTION 6.8. Counterparts. This Agreement may be executed in any number of counterparts, each of which as so executed shall be deemed to be an original, but such counterparts shall together constitute but one and the same instrument.

SECTION 6.9. Inspection of Agreement. A copy of this Agreement shall be available at all reasonable times at the principal corporate trust office of the Warrant Agent for inspection by any Warrantholder. The Warrant Agent may require such Warrantholder to submit his, her or its Warrant Certificate for inspection by it.

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IN WITNESS WHEREOF, the Company and the Warrant Agent have caused this Agreement to be signed by their respective duly authorized officers as of the day and year first above written.

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