<PAGE>   1

                                                                   Exhibit 10.18

                             DATED, October 27, 1999

                    PIONEER POLSKI FUNDUSZ NIERUCHOMOSCI S.A

                                      -and-

                 PIONEER REAL ESTATE ADVISORS POLAND SP. Z O.O.

              -----------------------------------------------------
                          INVESTMENT ADVISORY AGREEMENT

                                -in relation to-

                  The Pioneer Polski Fundusz Nieruchomosci S.A.

                 real estate portfolio in the Republic of Poland
              -----------------------------------------------------

                           Cameron Mckenna Sp. z o.o.
                             Warsaw Financial Center
                              ul. Emilii Plater 53
                                  00-113 Warsaw

                               T +48 (22) 520 5555

                               F +48 (22) 520 5556
<PAGE>   2

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT           Page 2 of 22
--------------------------------------------------------------------------------


THIS AGREEMENT is made the 27th day of October 1999

BETWEEN:

1.    PIONEER POLSKI FUNDUSZ NIERUCHOMOSCI S.A a joint stock company
      incorporated under the laws of the Republic of Poland with its seat in
      Warsaw (the "FUND")

and

2.    PIONEER REAL ESTATE ADVISORS POLAND Sp. z o.o., a company incorporated
      with limited liability under the laws of the Republic of Poland with its
      seat in Warsaw (the "INVESTMENT ADVISOR")

WHEREBY IT IS AGREED AS FOLLOWS:

1.    In this Agreement the following expressions have the meanings ascribed to
      them below:-

      1.1.  "RENT"

            A sum payable by an occupational tenant or other user or occupier of
            any property (or a part thereof) included in the Portfolio for the
            use of such property. For the avoidance of doubt this shall include
            separate fees payable in respect of car parking spaces and/or
            turnover rents. As a turnover rent is meant a rent based as a
            percentage of the sales turnover of the Tenant.

      1.2.  "ANCILLARY FEES"

            Closing fees, consulting fees, advisory fees, transaction fees,
            break-up fees and directors fees paid to the Investment Advisor by
            any Portfolio company, other than amounts in reimbursement of
            out-of-pocket expenses and fees earned by the Investment Advisor or
            its Affiliates pursuant to other agreements with the Fund.

      1.3.  "FUND DOCUMENTS"

            the Statute of the Fund, a revised and restated Subscription and
            Shareholders' Agreement, Investment Advisory Agreement, Pioneer
            Group Letter Agreement, Strategic Advisory Agreement, Umbrella
            Services Agreement.

      1.4.  "INVESTMENT ADVISOR"

            Where the context so requires, references to the Investment Advisor
            shall include its officers, shareholders and employees.

      1.5.  "STRATEGIC ADVISOR"

            means Pioneer Real Estate Advisors, Inc., a corporation incorporated
            with limited liability in the State of Delaware, United States of
            America.

      1.6.  "TENANTS"

            All persons occupying by virtue of Leases one or several properties
            (or a part thereof) comprised in the Portfolio.

      1.7.  "SENIOR INVESTMENT ADVISOR"

            Mr Gren Carr Jones or such other person appointed by the Investment
<PAGE>   3

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT           Page 3 of 22
--------------------------------------------------------------------------------


            Advisor from time to time.

      1.8.  "PURCHASERS"

            Persons to whom the Fund shall sell or attempt to sell any
            properties forming part of the Portfolio, and their authorised
            representatives and advisors.

      1.9.  "TERM"

            The period commencing at midnight on October 27, 1999 and ending at
            midnight on the date of distribution of all the assets of the Fund
            between the Shareholders.

      1.10. "SERVICE CHARGE"

            A charge payable by any Tenant of a property in the Portfolio under
            the terms of its lease for the provision by the Fund of services for
            the Portfolio including the Fund's costs and expenses of managing
            the Portfolio and any other fees and expenses to the extent
            permitted by the Leases.

      1.11. "FEES"

            The fees specified in the SCHEDULE 1 to this Agreement.

      1.12. "AFFILIATE"

            means, with respect to any Person, any other Person directly or
            indirectly controlling, controlled by or under common control with
            such Person. For the purposes of this Agreement. "CONTROL" shall
            mean the ability to direct the activities of the controlled Person
            by lawful means.

      1.13. "PERSON"

            means and includes (i) an individual, (ii) a legal entity,
            organisation, partnership, registered partnership or limited
            partnership, and (iii) the State Treasury or a local authority
            ("GOVERNMENTAL AUTHORITY") or any department or agency thereof.

      1.14. "PORTFOLIO"

            All such properties and/or companies ("PORTFOLIO COMPANIES")
            (including without limitation land and buildings and other
            facilities and improvements, agreements rights and interests
            relating thereto) as the Fund owns or shall own during the Term in
            the Republic of Poland. References to the Portfolio in this
            agreement shall (where the context so requires) include references
            to individual properties comprised therein or held by Portfolio
            Companies from time to time and to part or parts thereof.

      1.15. "FUND'S REPRESENTATIVE"

            Any one of not less than two people nominated in writing by the Fund
            to the Investment Advisor from time to time, to whom the Investment
            Advisor can look for instructions.

      1.16. "RESERVES"

            Those amounts considered prudent by the Investment Advisor to be
            maintained (in the Designated Account) with respect to the Portfolio
            for the operation, maintenance and improvement thereof from time to
            time.

      1.17. "VENDORS"

            Any Persons from whom the Fund shall acquire or seek to acquire any
<PAGE>   4

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT           Page 4 of 22
--------------------------------------------------------------------------------


            properties to form part of the Portfolio, and their authorised
            representatives and advisors.

      1.18. "LEASES"

            All leases of land or other agreements or rights under which Tenants
            lawfully occupy or use any premises contained in a property forming
            part of the Portfolio whether originally granted by the Fund or a
            Vendor, or created by operation of law.

      1.19. "ADVISORY SERVICES"

            The services described in the SCHEDULE 1 to this Agreement.

      1.20. "AUTHORITIES"

            The Polish Government or any of its ministries or agencies, the Tax
            Chamber, Gminas, Unions of Gminas, City Authorities, and any other
            bodies exercising lawful authority over any of the properties
            comprised in the Portfolio.

      1.21. "DESIGNATED ACCOUNT"

            An account or accounts at the Fund's bank, full details of which
            shall be provided by the Fund to the Investment Advisor from time to
            time in writing. For the avoidance of doubt the Designated Account
            shall be opened and maintained in the name and on behalf of the
            Fund.

      1.22. "CONTRACTORS"

            Third parties providing services to the Fund on terms and conditions
            which would be contracted between two independent parties in
            relation to the Portfolio.

2.    The Fund hereby appoints the Investment Advisor to act as the investment
      advisor of the Fund in relation to its Portfolio, for the Term or until
      earlier termination of this Agreement. The Investment Advisor accepts the
      appointment and agrees to provide the Advisory Services on the terms and
      conditions set out in this Agreement.

3.    Subject to Clause 6 below, for so long as this Agreement is in force the
      Fund shall pay the Investment Advisor the Fees at the times and in the
      manner set out in SCHEDULE 1 to this Agreement. Save as specifically
      agreed to the contrary in any other agreements with the Fund for the
      provision of other services, any Ancillary Fees received by the Investment
      Advisor, Pioneer Pierwsze Polskie Towarzystwo Funduszy Inwestycyjnych
      S.A., any of their Affiliates, or any of their employees from any of the
      Portfolio Companies shall be accounted for to the Fund, either by direct
      payment or by corresponding reductions in the Fees payable from time to
      time.

4.    The Management Board of the Fund shall promptly provide the Investment
      Advisor, on request, with all such written approvals authorisations and
      powers of attorney as may be necessary or desirable to permit the
      Investment Advisor to fulfil its obligations under this Agreement,
      provided the Management Board complies with all contractual documents and
      receives required approvals from Supervisory Board, Investment Committee
      and General Meeting of Shareholders.

5.    Costs and Expenses

      5.1.  The Fund will bear organisational and offering expenses of the Fund,
            including placements fees, up to an aggregate amount equal to 1% of
            the
<PAGE>   5

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT           Page 5 of 22
--------------------------------------------------------------------------------


            total commitments as prescribed in Clause 3 of the Subscription and
            the Shareholders Agreement dated as of October 27, 1999
            ("COMMITMENTS"), as from time to time amended. Such amount will be
            used to pay or to reimburse the Investment Advisor or its Affiliates
            for payment of third party legal, accounting, printing and similar
            offering and organisational costs, and an allocable share of the
            Investment Advisor's overhead and salary expenses to the extent
            attributable to the organisation of the Fund and the offering. Any
            such expenses in excess of the above amounts will be borne by the
            Strategic Advisor.

      5.2.  The Fund will bear transaction costs and expenses directly related
            to the purchase, holding or sale of Portfolio Company or a Portfolio
            or a part thereof, annual auditing fees of the Fund, bank charges,
            legal fees and expenses (e.g. leasing fees and property and facility
            management fees not reimbursed by Tenants), reasonable out-of-pocket
            expenses of the Investment Committee and the Supervisory Board,
            taxes payable by the Fund and nominal salaries of Management Board,
            Supervisory Board and Investment Committee personnel (not to exceed
            $5,000 US per member per year) (the "FUND EXPENSES").

      5.3.  All costs and expenses, including the Fees, all professional and
            other costs relating to properties in the Portfolio, the employment
            costs of building managers for such properties, and such office and
            telephone expenses as it shall be necessary to incur in order to
            provide such office as shall be required for the purpose of
            maintaining the registration of the Fund with the Urzad Skarbowy
            (tax office) or other such Authorities, shall be borne by the Fund
            and paid from the Designated Account.

      5.4.  All third party costs and expenses in relation to properties
            considered for acquisition by the Fund shall be borne by the Fund
            and paid from the Designated Account.

      5.5.  All costs and expenses of employing a suitably qualified person to
            provide leasing services to the Fund in relation to the Portfolio
            shall be borne by the Fund, if provision is made for the employment
            of such a person in the Fund's annual budget.

      5.6.  The annual budget for the Fund Expenses will be subject to the
            approval of the Supervisory Board of the Fund.

      5.7.  If funds in the Designated Account are insufficient, the Fund shall
            promptly provide the necessary funds at the Investment Advisor's
            request. The Investment Advisor is not obliged to advance funds to
            pay such costs and expenses. If it does so, the Fund shall promptly
            reimburse the Investment Advisor on request, and shall pay interest
            on funds so advanced at a rate equal to four percent (4%) above the
            prime rate for unsecured short term (3 months) loans from time to
            time announced by Citibank (Poland) SA in Warsaw until the date of
            reimbursement.

6.    The Investment Advisor shall exercise the powers granted hereunder and
      discharge its duties hereunder in the best interests of the Fund and, in
      connection therewith, shall exercise the degree of care, skill and
      diligence that a prudent investment advisor would exercise, having due
      regard at all times to the interests of the Fund in its capacity as
      landlord under the Leases and to the good name and institutional standing
      of the Fund.
<PAGE>   6

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT           Page 6 of 22
--------------------------------------------------------------------------------


7.    Conflicts of Interest

      7.1.  The Investment Advisor hereby accepts the obligations of the Pioneer
            Group, Inc. set out in the letter agreement between The Pioneer
            Group, Inc. and the Fund dated the date hereof (the "PIONEER GROUP
            LETTER AGREEMENT" a copy of which is appended to this agreement as
            Schedule 2) as direct obligations of the Investment Advisor only
            with respect to the direct actions of the Investment Advisor and not
            of any Affiliates.

      7.2.  Subject to Clauses 6 and 8, nothing in this Agreement shall preclude
            the Investment Advisor from providing independent advice on real
            estate investment to third parties in the Republic of Poland.

      7.3.  The Investment Advisor acknowledges that the Fund will not invest in
            any property owned by any of its Affiliates, or in a company any of
            whose shares are held thereby directly or indirectly, or which has
            borrowed funds therefrom without a prior resolution of the
            Supervisory Board pursuant to Article 8.10 (r) of the Fund's
            Statute.

      7.4.  In the event that the Investment Advisor recommends that the Fund
            shall invest in a property or company advised by the Investment
            Advisor or its Affiliates, it shall make full disclosure of the
            terms on which such services have been provided at the time of such
            recommendation.

8.    Confidentiality.

      8.1.  For purposes of this Clause 8, the term "CONFIDENTIAL INFORMATION"
            shall mean, by way of illustration and not limitation, all knowledge
            or information (whether or not patentable and whether or not
            copyrightable) owned, possessed or used by Investment Advisor,
            including without limitation, any invention, discovery, computer
            software, software documentation, data, technology, designs,
            innovations, improvements, vendor information, customer information,
            apparatus, equipment, trade secret, process, research, report
            technical data, know-how, marketing or business plan, forecast,
            unpublished financial statement, budget, license, price, cost and
            employee list that is disclosed by, or on behalf of the Fund to the
            Investment Advisor or that is otherwise obtained by the Investment
            Advisor in the course of performance of services hereunder, as well
            as all data derived therefrom.

      8.2.  The Investment Advisor undertakes that both during the term of this
            Agreement and after its termination it will:

            8.2.1.  preserve and cause its employees, agents and representatives
                    to preserve the confidentiality of any Confidential
                    Information;

            8.2.2.  use Confidential Information only for the Investment
                    Advisor's activities in accordance with the terms of this
                    Agreement.

      8.3.  The Investment Advisor's obligations under this Clause 8 shall not
            apply to any information that:

            8.3.1.  is or becomes known to the general public under
                    circumstances involving no breach by the Investment Advisor
                    or others of the terms of this Clause 8;

            8.3.2.  is generally disclosed to third parties by the Fund without
                    restriction on such third parties;
<PAGE>   7

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT           Page 7 of 22
--------------------------------------------------------------------------------


            8.3.3.  is disclosed on confidential terms to lawyers or other
                    professional advisors of the Fund or the Investment Advisor;

            8.3.4.  is disclosed as required by applicable laws or regulations,
                    courts of competent jurisdiction, regulatory authorities,
                    any stock exchange on which shares of the Fund are proposed
                    to be offered, or in connection with any arbitration between
                    the parties to this agreement;

            8.3.5.  is disclosed in pursuance of the Investment Advisor's
                    obligations under Clause 6 of this Agreement.

9.    The Investment Advisor shall:-

      9.1.  maintain staff with training and experience adequate for the
            performance of the Investment Advisor's obligations under this
            Agreement;

      9.2.  maintain full-time offices in Warsaw, the Republic of Poland
            throughout the Term;

      9.3.  be responsible for its own office and administrative expenses,
            including fees or other compensation paid to the Strategic Advisor,
            and the salaries, travel costs, benefits and other compensation of
            its employees (save to the extent that such are provided for in the
            annual budget of the Fund);

      9.4.  ensure that the Advisory Services are provided under the supervision
            of the Senior Investment Advisor;

      9.5.  ensure that copyright in all plans and documents prepared by or for
            the Investment Advisor in connection with the Portfolio is vested in
            the Fund and that all such documents (together with all accounts
            schedules and other records prepared or maintained by the Investment
            Advisor in relation to the Portfolio) are delivered to the Fund (or
            as directed by the Fund) at the expiry or termination of this
            Agreement;

      9.6.  accept instructions in relation to the management of the Portfolio
            only from the Fund's Representative and deliver all notices,
            reports, accounts and other communications to be provided to the
            Fund under the terms of this Agreement to the Fund's Representative
            or as s/he may direct;

      9.7.  inform in writing the Supervisory Board of the Fund:-

            9.7.1.  of any business activities in which it or its Affiliates are
                    involved which are not related to the Fund and which could
                    create an opportunity for conflicts of interest to arise in
                    relation to the Fund's investment activity, and

            9.7.2.  of any proposed Fund investments in which any Shareholder of
                    the Fund has a vested interest of which the Investment
                    Advisor is aware; and

      9.8.  provide copies to the Supervisory Board of the Fund of its annual
            financial statements;

      9.9.  throughout the Term at its own expense employ as Senior Investment
            Advisor an individual to be approved by the Fund (such approval is
            hereby given in relation to Mr. Gren Carr Jones and shall not be
            unreasonably withheld in future in relation to any suitably
            qualified person) PROVIDED ALWAYS that the Investment Advisor shall
<PAGE>   8

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT           Page 8 of 22
--------------------------------------------------------------------------------


            designate another of its employees acting as Senior Investment
            Advisor for any period between the departure from the Investment
            Advisor's employment of the Senior Investment Advisor and the
            appointment of a replacement and for any period when the Senior
            Investment Advisor is absent through illness or otherwise for a
            period in excess of 14 working days. The Senior Investment Advisor
            (or acting Senior Investment Advisor) or a person performing the
            duties of the Senior Investment Advisor shall be based in Warsaw and
            shall devote him or herself on at least 80% of full-time basis or
            more if it is necessary for the successful operation of the Fund to
            the performance of the Investment Advisor's duties under this
            Agreement;

      9.10. be entitled to consult the Fund's lawyers and accountants at the
            Fund's expense on all matters relating to the Portfolio, where such
            consultation is reasonably necessary for the proper performance by
            the Investment Advisor of its duties hereunder or for the protection
            of the interests of the Fund;

      9.11. be entitled to represent itself to third parties as the authorised
            agent of the Fund in relation to all matters pertaining to the
            performance by the Investment Advisor of its obligations hereunder
            and to require the Fund to grant any powers of attorney as may be
            required to evidence such authority to third parties;

      9.12. be entitled to rely upon the accuracy of, and act in accordance
            with, information supplied to it by the Fund;

      9.13. on request, prepare on behalf of the Fund and issue to its
            Shareholders first draft "trial balance" financial reports within
            five (5) days of the end of each quarter, on the strict
            understanding that neither the Investment Advisor nor any of its
            respective directors, officers and employees shall be held liable
            for the accuracy or completeness thereof;

      9.14. on request, prepare on behalf of the Fund and issue to its
            Shareholders separate editions of the Fund's financial reports (as
            required by the Fund Documents to be produced to Shareholders) which
            shall, to the Investment Advisor's best efforts, comply with
            International Generally Accepted Accounting Principles from time to
            time.

10.   The Investment Advisor will enter into a strategic advisory agreement with
      the Strategic Advisor, pursuant to which the Strategic Advisor will
      provide certain advisory and other services to the Investment Advisor. The
      Fund shall have no direct contractual relationship with the Strategic
      Advisor, who shall be a subcontractor to the Investment Advisor and
      compensated by the Investment Advisor from the Fees.

11.   The Investment Advisor represents and warrants to the Fund that it is duly
      established, organised and existing under the laws of the Republic of
      Poland and has all requisite power and authority under its Statute and the
      laws of the Republic of Poland to carry out the Advisory Services and to
      execute, deliver and perform this Agreement and each of the other Fund
      Documents to which it is or will be a party.

12.   All investment recommendations by the Investment Advisor in connection
      with the Fund shall be reviewed by and shall be subject to the prior
      approval of the Fund.
<PAGE>   9

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT           Page 9 of 22
--------------------------------------------------------------------------------


13.   Except as expressly authorised herein or as the Fund may delegate powers
      to the Investment Advisor, the Investment Advisor shall not be authorised
      to manage the affairs of, act in the name of or bind the Fund in any
      manner whatsoever.

14.   Termination

      14.1. The Fund shall be entitled to terminate this agreement at any time
            upon written notice to the Investment Advisor, accompanied by
            written evidence of a resolution passed by a two thirds (2/3)
            majority as provided for in the Fund's Statute of all the Fund's
            Shareholders (excluding any Affiliate of the Investment Advisor),
            but only either:

            14.1.1. for "good cause" (wazny powod), which for the purposes of
                    this provision shall be defined as-

                    14.1.1.1. a material breach by the Investment Advisor of its
                              material obligations under this Agreement or any
                              negligent act which is not promptly undertaken
                              (using reasonable endeavours) to be cured and is
                              not cured within sixty (60) days of the notice
                              from the Fund requiring that such breach be cured;
                              or

                    14.1.1.2. wilful misconduct, gross negligence or fraud (a)
                              of any employee of the Investment Advisor having
                              remained unremedied to the entire satisfaction of
                              the Fund after seven (7) business days prior
                              notice by the Fund to the Investment Advisor, or
                              (b) of a senior officer of the Investment Advisor
                              (including without limitation any member of the
                              Board of Management of the Investment Advisor) in
                              either case in relation to this Agreement; or

                    14.1.1.3. the Investment Advisor or Pioneer Real Estate
                              Advisors, Inc. shall become insolvent. For the
                              purposes of this clause, a Person shall be deemed
                              to be insolvent if (a) he is generally unable to
                              meet his obligations as they generally become due
                              or (b) has ceased paying his current obligations
                              in the ordinary course of business as they
                              generally become due, or (c) if the aggregate of
                              his assets is not, at a fair valuation, sufficient
                              (or if disposed of by a fairly-conducted sale by
                              legal process would not be sufficient) to enable
                              payment of all his obligations, due and accruing
                              and remains insufficient fifteen (15) days after
                              written notice by the Fund of its intention to
                              terminate this Agreement; or

                    14.1.1.4. the Investment Advisor ceases to be directly or
                              indirectly controlled by The Pioneer Group Inc.;

                    14.1.1.5. if the Investment Advisor:

                              14.1.1.5.1. has a receiver, administrative
                                          receiver or administrator appointed
                                          over all or any of its assets or
                                          undertakings; or

                              14.1.1.5.2. passes a resolution to wind up or has
                                          a liquidator appointed; or

                              14.1.1.5.3. ceases or threatens to cease trading.
<PAGE>   10

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT          Page 10 of 22
--------------------------------------------------------------------------------


            14.1.2. in the event that the following benchmarks have not been met
                    by the specified dates (whether or not by any fault on the
                    part of the Investment Advisor):-

                    14.1.2.1. if as of October 27, 2001 at least one third of
                              the Fund's capital shall have been invested
                              pursuant to Article 6 (a) and/or (c) of the
                              Statute of the Fund; or

                    14.1.2.2. if as of October 27, 2002 at least two-thirds of
                              the Fund's capital shall have been invested
                              pursuant to Article 6 (a) and/or (c) of the
                              Statute of the Fund;

            14.1.3. in the event that none of The Pioneer Group, Inc. or any of
                    its Affiliates any longer hold Class B shares in the Fund;

            14.1.4. in the event of a material breach by a Pioneer entity (as
                    defined in the Subscription and Shareholders' Agreement) or
                    its Affiliate of its/their material obligation/obligations
                    under the Fund Documents which is not cured within (sixty)
                    60 days of notice from the Fund to that Pioneer entity
                    requiring that such breach be cured;

            14.1.5. if any Property Management Agreement in the form of Schedule
                    3 to the Umbrella Services Agreement (where a Investment
                    Advisor's Affiliate is the Managing Agent) or any
                    Development Management Agreement in the form of Schedule 4
                    to the Umbrella Services Agreement (where a Investment
                    Advisor's Affiliate is the Development Manager) is
                    terminated by the Fund for good cause (as defined under the
                    relevant Agreement).

      14.2. In the event this Agreement is terminated other than for one or more
            of the reasons listed under Clause 14.1.1 above, the Investment
            Advisor shall be entitled to retain a percentage of the Incentive
            Fee equal to a fraction, the numerator of which is the total cost of
            all the investments made by the Fund prior to the effective date of
            termination, plus the total cost of all the investments made
            thereafter to the extent that the Investment Advisor identified (by
            submitting a proposal to the Investment Committee) such investments
            prior to such date, and the denominator of which is the total cost
            of all investments made by the Fund, in each case determined as of
            the date of payment of any amount of the Incentive Fee.

      14.3. The Investment Advisor shall be entitled to terminate this Agreement
            at any time upon ninety (90) days written notice to the Fund in the
            event that the Fund shall be in material breach of any of its
            monetary obligations under this Agreement and such breach shall not
            have been cured within 90 days of a written notice from the
            Investment Advisor to the Fund (copied to the members of the
            Supervisory Board of the Fund) requiring such breach to be cured and
            upon one hundred and eighty (180) days written notice to the Fund in
            the event that the Fund shall be in material breach of any of its
            non-monetary obligations under this Agreement and such breach shall
            not have been cured within 180 days of a written notice from the
            Investment Advisor to the Fund (copied to the members of the
            Supervisory Board of the Fund) requiring such breach to be cured.

      14.4. Any termination of this Agreement under the terms of this clause 14
            shall
<PAGE>   11

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT          Page 11 of 22
--------------------------------------------------------------------------------


            be without prejudice to the rights of either party hereto subsisting
            at the date of such termination.

15.   The Fund shall indemnify the Investment Advisor against all claims, costs,
      losses and other liabilities whatsoever arising in connection with the
      Portfolio or the management thereof, except insofar as they arise from
      fraud, wilful misconduct or negligence of the Investment Advisor.

16.   This Agreement is personal to the Fund and the Investment Advisor and is
      not assignable.

17.   In this Agreement any words importing one gender include all other genders
      and words importing the singular include the plural and vice versa.

18.   If at any time the Fund or the Investment Advisor are two or more
      individuals the terms the "FUND" and the "INVESTMENT ADVISOR" include the
      plural number and obligations expressed or implied to be made by or with
      such party are deemed to be made by or with such individuals jointly and
      severally.

19.   Governing Law

      This Agreement shall be governed in all respects by the Laws of the
      Republic of Poland.

20.   Arbitration

      Any claims or disputes between the parties arising out of or relating to
      this Agreement, which cannot be resolved in an amicable fashion shall be
      settled by an ad hoc arbitration court sitting in Warsaw, the Republic of
      Poland (the "ARBITRATION COURT"). The arbitration proceedings shall be
      conducted in accordance with the Rules of Arbitration of the United
      Nations Commission on International Trade Law (the "UNCITRAL ARBITRATION
      RULES") in force at the time of submittal of the dispute to arbitration.
      The proceedings shall be conducted in the English language. There shall be
      one arbitrator appointed jointly by such of the Parties as are in dispute.
      The President of the London Court of International Arbitration in London,
      England shall act as appointing authority under the UNCITRAL Arbitration
      Rules if the Parties in dispute fail to appoint the arbitrator jointly
      within the limits specified in the UNICITRAL Arbitration Rules. If the
      President of the London Court of International Arbitration will refuse or
      fail to appoint the arbitrator, either Party may request the
      Secretary-General of the Permanent Court of Arbitration at The Hague to
      designate an appointing authority in London, England, which shall then
      appoint the arbitrator. In case either Party challenges the appointed
      arbitrator, then the decision on the challenge shall be made by the
      appointing authority and in case any Party shall file an objection that
      the arbitrator has no jurisdiction or has exceeded its jurisdiction then
      the appointing authority shall rule on the objection.

21.   Entire Agreement

      21.1. Any amendments to this Agreement shall be made in writing and signed
            by each of the parties to be valid.

      21.2. This Agreement, the Schedules hereto, and all documents and
            agreements entered into or to be entered into pursuant thereto,
            represent the entire understanding and agreement between the parties
            with respect to the subject matter of this Agreement.

      21.3. From the date hereof this Agreement supersedes any and all prior
<PAGE>   12

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT          Page 12 of 22
--------------------------------------------------------------------------------


            agreements between the parties, which said agreements (if any) are
            hereby terminated and of no further force and effect.

22.   Severability

      Any provision of this Agreement that is prohibited or unenforceable under
      the laws of any jurisdiction which affects the performance or
      enforceability of this Agreement shall, as to such jurisdiction, be
      ineffective to the extent of such prohibition or unenforceability without
      invalidating the remaining portions hereof or affecting the validity or
      enforceability of such provision in any other jurisdiction.

23.   Waiver

      Any of the provisions of this Agreement may be waived by the party or
      parties entitled to the benefit thereof. No waiver of any provision shall
      be construed as a waiver of any other provision. Any waiver must be in
      writing to be valid.

24.   Counterparts

      This Agreement has been signed in two English and Polish language copies,
      one for each of the parties. In the event of any discrepancies between the
      English and Polish versions, English version shall prevail.

25.   Interpretation

      25.1. The Index and Article headings contained in this Agreement are for
            convenience only and shall not affect the construction of this
            Agreement;

      25.2. The schedule is deemed to be incorporated into this Agreement, and a
            reference to this "AGREEMENT" includes a reference to the schedule;

      25.3. References to any funds being "INVESTED" shall mean "INVESTED OR
            COMMITTED TO BE INVESTED".

26.   Notices

      Unless provided otherwise all notices and other communications given or
      made pursuant hereto shall be in writing and shall be deemed to have been
      given or made if in writing and delivered personally or sent by telefax,
      reputable overnight courier (including but not limited to DHL or Federal
      Express), registered or certified mail (postage pre paid, return receipt
      requested) to the parties at the following addresses:

IF TO THE FUND:-
PIONEER POLSKI FUNDUSZ NIERUCHOMOSCI S.A.
Plac Trzech Krzyzy 8,
00-499 Warsaw, Poland
Att: "Zarzad"
Telephone: +48 (22) 627 27 50
Telefax::  +48 (22) 627 27 60

WITH A COPY TO
Pioneer Real Estate Advisors, Inc.
60 State Street
Boston, MA 02-139, USA
<PAGE>   13

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT          Page 13 of 22
--------------------------------------------------------------------------------


Att.   Mr Amos J. Rogers III
Telephone: +1(617) 742 78 25
Telefax::  +1(617) 422 42 86

Towarzystwo Obrotu Nieruchomosciami AGRO S.A.
22 Sielecka St.
00-738 Warsaw, Poland
Att.: Mr. Jan Wojciech Podobas
      the President of the Board of Management
Tel.: + 48(22) 699 4123
Fax:  + 48(22) 699 4122

CADIM Servotech B.V.
800, Square Victoria, Suite 4400
P.O.B. 118
Montreal, Quebec, Canada H4Z 1B7
Att.: V.P. Legal
Tel.: (514) 875-3319
Fax:  (514) 875-3328

cc:
CADIM Servotech B.V.
Herengracht 483
1017 BT Amsterdam
The Netherlands
Att.: Mr. J. Bradley Unsworth
Tel.:
Fax:

Lafleur Brown
1 Place Ville Marie, 37 floor
H3B 3P4 Montreal, Quebec, Canada
Tel.: (514) 878 9641
Fax:  (514) 878 1450

Beata Gessel and Partners
8 Widok St.
00-023 Warsaw, Poland
Tel.: + 48 22 690 69 01
Fax:  + 48 22 690 69 31

European Bank for Reconstruction and Development
One Exchange Square
London, EC2A 2JN
Great Britain
Att.: Operation Administrative Unit
Tel.: + 44 20 733 86 000
Fax:  + 44 20 733 86 100

Fundacja na Rzecz Nauki Polskiej
ul. Grazyny 11
<PAGE>   14

Exhibit 12                  INVESTMENT ADVISORY AGREEMENT         Page 14 of 22
--------------------------------------------------------------------------------


02-548 Warszawa, Polska
Att.: Mr. Maciej W. Gralski

IF TO THE INVESTMENT ADVISOR:

Pioneer Real Estate Advisors Poland Sp. Z O.O.
Plac Trzech Krzyzy 8,
00-499 Warsaw, Poland
Attn: Mr Gren Carr Jones
Telephone: +48 (22) 627 27 50
Tel./fax:  +48 (22) 627 27 60

WITH A COPY TO
The Pioneer Group
60 State Street
Boston MA 02109
The United States of America
Attn: Mr Bob Nault
Telephone: +(1) 617 742-7825
Telefax:   +(1) 617 422-4286

WITH A COPY TO
Pioneer Real Estate Advisors, Inc.
60 State Street
Boston, MA 02-139, USA
Att. Mr Amos J. Rogers III
Telephone: +1 (617) 742 78 25
Telefax::  +1 (617) 422 42 86

All notice and communications shall be deemed delivered on the day of the
receipt thereof by the addressee. All notice and communications shall be copied
to all the shareholders of the Fund.

AS WITNESS the hands of authorised signatories for the Fund and the Investment
Advisor today.
<PAGE>   15

Exhibit 12                  INVESTMENT ADVISORY AGREEMENT         Page 15 of 22
--------------------------------------------------------------------------------


PIONEER POLSKI FUNDUSZ NIERUCHOMOSCI S.A.


Signature: /s/ Alicja Malecka-Salomon
           -----------------------------------

Name: Alicja Malecka-Salomon

Title: Vice President of the Management Board


Signature: /s/ Amos Rogers
           -----------------------------------

Name: Amos Rogers

Title: Member of the Management Board


PIONEER REAL ESTATE ADVISORS POLAND SP. Z O.O.


Signature: Gren Carr-Jones
           -----------------------------------

Name: Gren Carr-Jones

Title: Member of the Management Board
<PAGE>   16

Exhibit 12                  INVESTMENT ADVISORY AGREEMENT         Page 16 of 22
--------------------------------------------------------------------------------


                                   SCHEDULE 1

                                SERVICES AND FEES

I. ADVISORY SERVICES

      Subject to the supervision of the Investment Committee and Supervisory
      Board of the Fund, the Investment Advisor shall provide fund management
      services to the Fund including services set out below:

1.    Identifying and evaluating investment opportunities in the Republic of
      Poland which comply with the Investment Guidelines (attached as Exhibit to
      the Subscription and Shareholders' Agreement) and the Environmental
      Procedures set forth in Annexes A & B to this Schedule 1, including
      without limitation (a) analysing and investigating investment
      opportunities; (b) structuring investments held directly by the Fund; (c)
      structuring investments held in Portfolio Companies; (d) negotiating,
      structuring and supervising the documentation of debt financing, or
      refinancing for Fund investments, (e) conducting due diligence,
      negotiating the terms of, and supervising the preparation and review of,
      all documents required to complete investment transactions of the Fund;
      and

2.    Developing and implementing accounting and information management systems,
      including systems to maintain detailed accounts of income and expenses in
      relation to individual properties comprising the Portfolio; and

3.    Monitoring the performance of investments of the Fund and providing advice
      to the Fund with respect to corporate and financial matters and overall
      strategic advice, including in connection with any refinancing or
      restructuring of any Fund investment; also, where appropriate (a)
      negotiating any active role in the management of Portfolio Companies,
      including having representatives of the Investment Advisor or Strategic
      Advisor serve on the boards or directors or other corporate governance
      bodies of Portfolio Companies, and (b) providing advice to the management
      of Portfolio Companies, with respect to corporate and financial matters
      and overall strategic advice, including in connection with any refinancing
      or restructuring of a Portfolio Company's capital structure; and

4.    Evaluating, structuring and supervising the timing and method of
      disposition or liquidation of investments of the Fund; and

5.    Providing portfolio management services to the Fund, including strategic
      advice relating to the balance of commercial, retail, residential and
      industrial real estate included in the Portfolio; and

6.    Preparing or providing assistance to the Fund in the preparation of the
      Fund's Annual Budget, annual financial statements, investment reports and
      annual environmental reports (as contemplated in the Environmental
      Procedures attached hereto).
<PAGE>   17

Exhibit 12                  INVESTMENT ADVISORY AGREEMENT         Page 17 of 22
--------------------------------------------------------------------------------


II. FEES

1.    THE ADVISORY FEE

      1.1.  During the Investment Period, as defined in the Subscription and
            Shareholders Agreement, the Investment Advisor will be entitled to
            an annual base advisory fee equal to 2 % of the Fund's "Net Capital"
            (as hereinafter defined). "NET CAPITAL" means the sum of (i) total
            Commitments, as specified in Article 3 of the Subscription and
            Shareholders Agreement (which shall be reduced, after the last day
            on which Commitments can be called for, by the amount of Commitments
            which are not called for), (ii) the amount of the net capital gains
            of the Fund which are reinvested in real estate investments or any
            Portfolio Company, and (iii) net ordinary income reinvested in real
            estates by the Fund or any Portfolio Company, minus the sum of (a)
            the cost basis of investments which have been disposed of, the
            proceeds of which are distributed to the Shareholders, (b) realised
            losses on Fund investments and (c) the amount of Commitment
            cancelled and/or returned pursuant to the terms of the Subscription
            and Shareholders' Agreement dated October 27th 1999. The base
            advisory fee is payable quarterly in advance on the last day of the
            calendar quarter preceding the calendar quarter for which the
            payments is made. Base advisory fee will be paid out of Fund
            revenues or paid-in Commitments. Commitments mean the amounts
            expressed in United States Dollars committed by the Shareholders in
            the Fund for investment into the Fund pursuant to the Subscription
            and Shareholders Agreement referred to above.

      1.2.  After completion of the Investment Period, the annual base advisory
            fee will be reduced to 1.5% of the Fund's Net Capital.

      1.3.  In case a Commitment is reduced pursuant to the terms of the
            Subscription and Shareholders' Agreement, the amount of the Advisory
            Fee will be calculated on the amount actually subscribed by each
            Shareholder. The adjustment of the Advisory Fee shall take place
            after 6 months from the reduction of the subscription. In case a
            Commitment is reduced due to a Shareholder's default, the annual
            base Advisory Fee shall remain unchanged. However, the amount of the
            Advisory Fee due from the defaulted Commitment shall only be paid
            from any penalty payments received from the defaulting Shareholder.
            For the avoidance of doubt the remaining Shareholders and the Fund
            will not be liable to pay this proportion of the Advisory Fee, which
            will be due only from the penalty paid by the defaulting
            Shareholder.

2.    INCENTIVE FEE

      2.1.  The Investment Advisor shall be entitled to an annual incentive
            advisory fee (the "INCENTIVE FEE"). The Incentive Fee shall be equal
            to 25% of all amounts to be available for distribution by the Fund
            to its Shareholders after payment of the Incentive Fee from and
            after the date on which the Incentive Fee becomes payable. (For
            example purposes only: when the Incentive Fee becomes payable and
            the Fund has $100 available for distribution before payment of the
            Incentive Fee it shall distribute $80 to the Shareholders and $20 to
            the Investment Advisor as Incentive Fee as $20 is equal to 25% of
            $80, which is the amount available for distribution after payment of
            the Incentive Fee).
<PAGE>   18

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT          Page 18 of 22
--------------------------------------------------------------------------------


      2.2.  The Incentive Fee shall become payable on the date on which the Fund
            has paid aggregate dividends or distributions for all subscribed
            shares equal to US$ 28.88 per share plus a 10% per annum US$
            cumulative return compounded annual thereon (i.e. return of original
            investment capital plus 10% per annum preferred compounded annually
            return) and otherwise referred to as IRR as described in Section II
            paragraph 2.4 below.

      2.3.  Furthermore, the Incentive Fee shall increase to 27.5% of all
            amounts available for distribution to Shareholders after payment of
            the Incentive Fee on the date on which the Fund's Shareholders have
            received aggregate dividends or distributions which provide a 28%
            US$ internal rate of return (IRR).

      2.4.  For the purposes of this Agreement the IRR is the percentage rate at
            which the positive (outflows from the Fund to Shareholders) or
            negative (inflows from Shareholders to the Fund) cash flows to/from
            the Shareholders must be discounted so that the net present value of
            those cash flows would be equal to zero. The IRR shall be calculated
            using the IRR function of Microsoft Excel. All cash flows shall be
            recorded as of the last day of the quarter in which they are paid by
            or paid to the Shareholders. Cash inflows shall include actual
            capital funded by Shareholders (exclusive of any penalties) and cash
            outflows shall include cash distributions made to Shareholders
            inclusive of interim dividends and residual or liquidation proceeds.

      2.5.  Such IRR shall be calculated on the basis of the amounts paid in by
            the Shareholders in the Fund and expressed in US Dollars pursuant to
            the Exchange Rate as specified in the Subscription and Shareholders
            Agreement, and amounts paid out to Shareholders shall be expressed
            in US dollars calculated in accordance with the average exchange
            rate of the National Bank of the Republic of Poland on the last
            working day preceding the day of making payment (which for the
            purpose of this Agreement is a day of debiting of Fund's account).

      2.6.  The Incentive Fee (if any) will be paid as and when corresponding
            distributions are made to the Shareholders.

3.    PRIORITY OF DISTRIBUTIONS

      3.1.  The priority of distributions from the Fund shall be as follows:

            3.1.1.  first, to return the original capital of the Shareholders
                    equal to $28.88 per share;

            3.1.2.  second, to provide a 10% cumulative annual return (IRR) to
                    the Shareholders as described in Section II paragraph 2.2
                    above;

            3.1.3.  third, to accommodate the Incentive Fee allocation as
                    described in Section II paragraph 2.1 above; and

            3.1.4.  fourth, to accommodate the Incentive Fee allocation as
                    described in Section II paragraph 2.3 above.

            In the event that upon liquidation the Shareholders have not
            received a 10% IRR and if the Investment Advisor has received
            Incentive Fee distributions, the Investment Advisor undertakes to
            promptly remit to the Fund, funds required to provide the
            Shareholders with a 10% IRR, but in
<PAGE>   19

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT          Page 19 of 22
--------------------------------------------------------------------------------


            no event exceeding the amount of Incentive Fee received from the
            Fund.
<PAGE>   20

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT          Page 20 of 22
--------------------------------------------------------------------------------


                                     ANNEX A

                         EBRD's ENVIRONMENTAL PROCEDURES
<PAGE>   21

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT          Page 21 of 22
--------------------------------------------------------------------------------


                                     ANNEX B

                      SERVOTECH'S ENVIRONMENTAL PROCEDURES
<PAGE>   22

Exhibit 12                 INVESTMENT ADVISORY AGREEMENT          Page 22 of 22
--------------------------------------------------------------------------------


                                   SCHEDULE 2

                         PIONEER GROUP LETTER AGREEMENT