<PAGE>   1
                                                                   Exhibit 10.55


                              EMPLOYMENT AGREEMENT
                              --------------------

         AGREEMENT made as of August [ ], 2000 between Calypso Management LLC
(the "Company"), a Delaware limited liability company having its principal place
of business in Boston, Massachusetts, and Stephen G. Kasnet ("Executive").

                                   Background

         WHEREAS, prior to the consummation of the transaction (the "Merger")
contemplated by the Agreement and Plan of Merger (the "Merger Agreement") dated
as of May 14, 2000 by and between UniCredito Italiano S.p.A and The Pioneer
Group, Inc. ("Pioneer"), Pioneer intends to distribute to its stockholders all
of the outstanding shares of its wholly-owned subsidiary Harbor Global Company
Ltd. ("Harbor Global"); and

         WHEREAS, Executive now serves as the President of Pioneer Global
Investments, a division of Pioneer which operates substantially all of the
assets that Harbor Global will own or operate following the distribution; and

         WHEREAS, the Company has entered into an Administration and Liquidation
Agreement with Harbor Global, pursuant to which the Company has agreed to
provide certain specified services with respect to the liquidation of Harbor
Global's assets and the operation of those assets prior to their liquidation,
including but not limited to providing the services of the Executive to serve as
the President and Chief Executive Officer of Harbor Global; and

         WHEREAS, Harbor Global, the Company and the Executive recognize the
importance of Executive to Harbor Global and to its ability to operate and
liquidate the assets, and desire that the Company employ Executive upon and
subject to the terms herein provided; and

         WHEREAS, the Executive has agreed to be employed by the Company on the
terms and conditions set forth herein, including without limitation, the payment
of the Signing and Retention Bonus (as defined herein).
<PAGE>   2
                                   Agreements
                                   ----------

         In consideration of the premises, mutual covenants and agreements
hereinafter set forth and other good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, and in consideration of Harbor
Global's agreement to enter into the Administration and Liquidation Agreement,
the parties hereto covenant and agree as follows:

         Section 1.    Employment; Compensation. The Company hereby engages the
Executive as the President and Chief Executive Officer of the Company and the
Executive hereby accepts such engagement upon the terms and conditions of this
Agreement for the Term (as defined in the Administration and Liquidation
Agreement). The Company will pay Executive for provision of the services
hereunder an annual salary of $325,000, with an annual bonus opportunity of up
to $325,000 (as determined by the Board of Directors of Harbor Global (the
"Board") in accordance with the Administration and Liquidation Agreement),
subject to such payroll and withholding deductions as are required by law.

         Subject to the terms and conditions set forth in the Escrow Agreement
of even date herewith by and among the Company, Harbor Global, Executive and
State Street Bank and Trust Company, the Company shall pay to Executive a
signing and retention bonus in the amount of $1,800,000 (the "Signing and
Retention Bonus"). In addition, the Executive shall be entitled to receive 50%
of all amounts paid to the Company as an "Allocation" as defined in and pursuant
to the Administration and Liquidation Agreement (Executive's Share of
Allocations"), provided, however, that the Executive's Share of Allocations
shall be reduced in the amount of the Signing and Retention Bonus by reducing
the percentage of such Allocations to which the Executive is entitled to 33-1/3%
of Allocations paid pursuant to Section 7(ii) of the Administration and
Liquidation Agreement.

         Section 2.    Office and Duties. During the Term, Executive shall hold
such positions and perform such duties relating to the Company's and Harbor
Global's business and operations as may be consistent with the position of
President and Chief Executive Officer of the Company and as from time to time
may be assigned to him by the Company's managers or the Board, including but not
limited to serving as the President and Chief Executive Officer of Harbor
Global. In connection with providing such services to Harbor Global, the
Executive agrees that Harbor Global may purchase "key man" life or disability
insurance policies on him and further agrees that he shall cooperate in all
reasonable ways to allow Harbor Global

                                       2
<PAGE>   3
to acquire such insurance policies. While employed by the Company or performing
services for Harbor Global, the Executive shall devote substantially all of his
business time to his duties hereunder and shall not render services to, or be
otherwise engaged by, other persons or entities without the express written
consent of the Company and the Board, provided, however, that it shall not be a
violation of this Agreement for the Executive to engage in the activities set
forth on Exhibit A hereto.

         Section 3.        Benefits.

         (a)      Executive shall participate, to the extent he is eligible and
in a manner and to an extent that is fair and appropriate in light of the
position and duties granted to him hereunder, in all bonus, pension,
profit-sharing, group insurance, or other fringe benefit plans which the Company
may hereafter in its absolute discretion make available generally to its
executives, but the Company will not be required to establish any such program
or plan. Executive shall be entitled to such vacations and to reimbursement of
such expenses as Company policies allow to executives having comparable
responsibilities and duties.

         (b)      For the period beginning on the date hereof and ending on the
second anniversary of the date hereof, the Company shall provide insurance on
the life of Executive in the amount of $1,800,000.

         Section 4.        Termination of Employment.

         (a)      Notwithstanding any other provision of this Employment
Agreement, Executive's employment may be terminated by the Company during the
Term only in the following circumstances, at the direction of Board:

         (i)      At any time in the event of Executive's material breach of any
                  of the material terms of this Employment Agreement; his
                  causing a material breach of any duties owed under the
                  Administration and Liquidation Agreement (subject to the
                  notice and cure periods specified in the Administration and
                  Liquidation Agreement); his conviction of a felony, or his
                  failure to carry out any reasonable direction by the Board
                  with respect to the services to be rendered by him pursuant to
                  the Administration and Liquidation Agreement or the manner of
                  rendering such services.

                                       3
<PAGE>   4
         (ii)     Upon thirty (30) days' notice to Executive if he should be
                  unable, for one or more periods aggregating three months
                  during any consecutive twelve (12) month period, because of
                  illness, accident, or other disability (mental or physical),
                  to discharge substantially all of his duties hereunder, and
                  such disability is continuing at the time of such notice.

         (b)      Notwithstanding any other provision of this Employment
Agreement, Executive may terminate his employment by the Company at any time
following the first two years of the Term, upon giving 120 days' notice to the
Company and to the Board, provided, however, that Executive may terminate his
employment under extraordinary and unforeseen personal circumstances at any time
during the first two years of the Term, with the consent of the Board, not to be
unreasonably withheld, denied or delayed.

         (c)      Upon termination of Executive's employment with the Company
for any reason, his resignation as an officer, director, trustee, and/or any and
all other positions held by him with Harbor Global shall become effective.
Executive shall execute any and all documents and take any and all action
reasonably requested by Harbor Global to effectuate or acknowledge such
resignation.

         Section 5.    Confidentiality. Except in performance of services for
the Company or as required to be disclosed under applicable law, Executive shall
not, either during the period of his employment with Company or thereafter, use
for his own benefit or disclose to or use for the benefit of any person outside
the Company, or Harbor Global, as applicable, proprietary or confidential
information of the Company or Harbor Global and which is not otherwise in the
public domain.

         Section 6.    Non-Competition Covenants. Until the earlier of (i) two
(2) years following the termination of Executive's employment with (a) the
Company or (b) Harbor Global, or (ii) the sale of Assets representing
substantially all of the value of the Assets (as determined by the Board in good
faith), the Executive shall not, directly or indirectly, (x) provide services to
any person or entity with respect to assets substantially similar to assets held
at the time in question by Harbor Global, without the express prior written
consent of the Board, not unreasonably withheld, delayed or conditioned; or (y)
provide services with respect to any assets sold by Harbor Global, to any person
or entity which acquires such asset from Harbor Global, for two years after any
such acquisition, without the express prior written consent of the Board, not
unreasonably withheld, delayed or conditioned.

                                       4
<PAGE>   5
         Section 7.    Notices.  All notices hereunder, to be effective, shall
be in writing and shall be mailed by first class certified mail, postage prepaid
or sent via facsimile (with confirmation of receipt) as follows:

         (i)      if to the Company, addressed to it at:

                  Calypso Management LLC
                  60 State Street
                  Boston, Massachusetts 02109-1820
                  Attn: Stephen G. Kasnet


                  with a copy to:

                  Hill & Barlow
                  One International Place
                  Boston, Massachusetts 02110
                  Attn: Valerie Andrews
                  Facsimile: (617) 428-3500

         (ii)     if to the Board, addressed to it at:

                  Harbor Global Company Ltd.
                  60 State Street
                  16th Floor
                  Boston, Massachusetts 02109-1820
                  Attention: General Counsel

                  with a copy to:

                  Skadden, Arps, Slate, Meagher & Flom LLP
                  One Beacon Street
                  Boston, Massachusetts 02108-3194
                  Attn: Louis Goodman
                  Facsimile: (617) 573-4822

                                       5
<PAGE>   6
         (iii)    if to the Executive, addressed to him at:

                  Stephen G. Kasnet
                  1 University Lane
                  Manchester, MA 01944
                  Facsimile: (978) 526-1456

Notices sent in accordance with this Section 7 shall be deemed delivered (i)
four business days after deposit in the mail or (ii) on the date of confirmation
of the telecopy facsimile.

         Section 8.    Assignability.  This Employment Agreement shall not be
assignable by the Executive or the Company except as agreed in writing by both
parties.

         Section 9.    Entire Agreement.  This Employment Agreement and the
Escrow Agreement contain the entire agreement between the Company and Executive
with respect to the subject matter hereof.

         Section 10.   Dispute Resolution. Any dispute, controversy or claim
arising out of or relating to this Agreement, or the breach, termination or
validity hereof, shall be finally settled by arbitration in accordance with the
Commercial Arbitration Rules of the American Arbitration Association then in
effect, as modified herein (the "Rules"). The place of arbitration shall be
Boston, Massachusetts. There shall be one arbitrator, who shall be appointed by
agreement of the parties within thirty days of receipt by the respondent(s) of
the Demand for Arbitration. If such arbitrator is not appointed within the time
limit provided herein, such arbitrator shall be appointed by the American
Arbitration Association (the "AAA") in accordance with the striking and ranking
procedure contained in the Rules. Any arbitrator appointed by the AAA shall be a
retired judge or a practicing attorney with no less than fifteen years of
experience and an experienced arbitrator. The Arbitrator shall be required to
follow the law of The Commonwealth of Massachusetts. The arbitrator is not
empowered to award damages in excess of compensatory damages, and each party
hereby irrevocably waives any right to recover punitive, exemplary or similar
damages with respect to any dispute. Any arbitration proceedings, decision or
award rendered hereunder and the validity, effect and interpretation of this
arbitration agreement shall be governed by the Federal Arbitration Act, 9 U.S.C.
Section 1 et seq. Any award rendered hereunder shall be final and binding on the
parties and judgment upon such award may be entered in any court of competent
jurisdiction.

                                       6
<PAGE>   7
Notwithstanding anything to the contrary contained herein, the provisions of
this Section 10 shall not govern any action for equitable relief hereunder.

         Section 11.   Waivers and Further Agreements. Neither this Employment
Agreement nor any term or condition hereof, including without limitation the
terms and conditions of this Section 11, may be waived or modified in whole or
in part as against Company or Executive except by written instrument executed by
or on behalf of the party other than the party seeking such waiver or
modification, expressly stating that it is intended to operate as a waiver or
modification of this Employment Agreement or the applicable term or condition
hereof, it being understood that any action under this Section 11 affecting the
rights of Harbor Global hereunder may be taken only with the prior written
approval of the Board on behalf of Harbor Global as the intended third party
beneficiary of this Agreement. Each of the parties hereto agrees to execute all
such further instruments and documents and to take all such further action as
the other party may reasonably require in order to effectuate the terms and
purposes of this Employment Agreement as stated herein.

         Section 12.   Amendments. This Employment Agreement may not be amended,
nor shall any change, modification, consent, or discharge be effected except by
written instrument executed by or on behalf of the party against whom
enforcement of any change, modification, consent or discharge is sought, it
being understood that any action under this Section 12 affecting the rights of
Harbor Global hereunder may only be made with the prior written approval of
Harbor Global.

         Section 13.   Severability. If any provision of this Employment
Agreement shall be held or deemed to be invalid, inoperative or unenforceable in
any jurisdiction or jurisdictions, because of conflicts with any constitution,
statute, rule or public policy or for any other reason, such circumstance shall
not have the effect of rendering the provision in question unenforceable in any
other jurisdiction or in any other case or circumstance or of rendering any
other provisions herein contained unenforceable to the extent that such other
provisions are not themselves actually in conflict with such constitution,
statute or rule of public policy, but this Employment Agreement shall be
reformed and construed in any such jurisdiction or case as if such invalid,
inoperative, or unenforceable provision had never been contained herein and such
provision reformed so that it would be enforceable to the maximum extent
permitted in such jurisdiction or in such case.

         Section 14.   Governing Law.  The execution, interpretation, and
performance of this Agreement and any claims arising out of this Agreement shall
be

                                       7
<PAGE>   8
governed by the laws of The Commonwealth of Massachusetts without regard to the
conflict of law provisions thereof. The Company and the Executive hereby consent
to the jurisdiction of any state or federal court located within Suffolk County,
Massachusetts, waive personal service of process, and assent that service of
process may be made by registered mail to the parties' respective addresses as
provided in Section 7 above and shall be effective in the same manner as notices
are effective under such Section 7.

         Section 15.   Intended Third Party Beneficiary. Wherever Harbor Global
is mentioned in this Agreement, such provisions shall inure to and be for the
benefit of Harbor Global as if Harbor Global was party to this Agreement. The
parties understand and expressly agree that Harbor Global is intended to be a
third party beneficiary of this Agreement in such instances and shall have the
right to specifically enforce the provisions hereof.

         Section 16.   Effectiveness.  In the event that the transactions
contemplated by the Distribution Agreement (as defined in the Merger Agreement)
are not consummated, this Agreement shall be void and of no further force and
effect.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]



                                       8
<PAGE>   9
         IN WITNESS WHEREOF, the parties have executed this Employment Agreement
as a sealed instrument as of the date first above written.


EXECUTIVE:                            CALYPSO MANAGEMENT LLC


---------------------------           -------------------------------------
Stephen G. Kasnet                     By:    Donald H. Hunter
                                             Chief Operating Officer and
                                             Chief Financial Officer



                                       9
<PAGE>   10
                                    EXHIBIT A


Non-Executive Chairman of the Board of Directors, Warren Bancorp and Warren
Five Cents Savings Bank

Director, Bradley Real Estate, Inc. (or its successor)


                                       10