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                                 Exhibit 10.8

                PRENTISS PROPERTIES ACQUISITION PARTNERS, L.P.

        NINTH AMENDMENT TO THE SECOND AMENDED AND RESTATED AGREEMENT OF
     LIMITED PARTNERSHIP OF PRENTISS PROPERTIES ACQUISITION PARTNERS, L.P.

                                   RECITALS

          A.   Belair Real Estate Corporation desires to assign and Belmar
Realty Corporation ("ASSIGNEE") desires to acquire 0 Series B Cumulative
Redeemable Perpetual Preferred Units and 0 Series C Cumulative Redeemable
Perpetual Preferred Units (collectively, the "BELAIR UNITS") of Prentiss
Properties Acquisition Partners, L.P. (the "PARTNERSHIP").

          B.   Belcrest Realty Corporation desires to assign and Assignee
desires to acquire 500,000 Series B Cumulative Redeemable Perpetual Preferred
Units and 0 Series C Cumulative Redeemable Perpetual Preferred Units
(collectively, the "BELCREST UNITS") of the Partnership.

          C.   Argosy Realty Corporation desires to assign and Assignee
desires to acquire 0 Series B Cumulative Redeemable Perpetual Preferred Units
(the "ARGOSY UNITS") of the Partnership.

          D.   Belport Realty Corporation desires to assign and Assignee
desires to acquire 0 Series B Cumulative Redeemable Perpetual Preferred Units
(the "BELPORT UNITS") of the Partnership.

          E.   Belrieve Realty Corporation desires to assign and Assignee
desires to acquire 0 Series B Cumulative Redeemable Perpetual Preferred Units
(the "BELRIEVE UNITS") of the Partnership.

          Pursuant to Article XI of the Second Amended and Restated Agreement of
Limited Partnership, as amended (as so amended, the "AGREEMENT"), of the
Partnership, Prentiss Properties I, Inc. as the sole general partner of the
Partnership (the "GENERAL PARTNER"), desires to amend the Agreement to admit
Assignee as a Substitute Limited Partner with respect to the Belair Units,
Belcrest Units, Argosy Units, Belport Units and Belrieve Units.

          NOW, THEREFORE, the General Partner hereby adopts the following
amendment to the Agreement.

          1.   Exhibit A to the Agreement is hereby amended and restated
in its entirety as set forth on EXHIBIT A attached hereto.

          2.   Assignee accepts and agrees to be bound by the terms and
provisions of the Agreement.

                           [Signature Page Follows]

                                       1
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          IN WITNESS WHEREOF, the General Partner and the Assignee have executed
this Ninth Amendment as of March 17, 2000.

                                   GENERAL PARTNER

                                   PRENTISS PROPERTIES I, INC.

                                        By:  /s/ MICHAEL A. ERNST
                                            -----------------------------------
                                        Name:    Michael A. Ernst
                                        Title:   Chief Financial Officer

                                   ASSIGNEE AND SUBSTITUTE LIMITED PARTNER:

                                   BELMAR REALTY CORPORATION

                                        By:  /s/ WILLIAM CROSS
                                            -----------------------------------
                                        Name:    William Cross
                                        Title:   Vice President

                                       2<PAGE>

                                 Exhibit 10.9

                PRENTISS PROPERTIES ACQUISITION PARTNERS, L.P.

    TENTH AMENDMENT TO THE SECOND AMENDED AND RESTATED AGREEMENT OF LIMITED
         PARTNERSHIP OF PRENTISS PROPERTIES ACQUISITION PARTNERS, L.P.

                                   RECITALS

          A.   Belcrest Realty Corporation ("ASSIGNOR")desires to assign and
Belmar Realty Corporation ("ASSIGNEE") desires to acquire 350,000 Series B
Cumulative Redeemable Perpetual Preferred Units (THE "ASSIGNED UNITS") of
Prentiss Properties Acquisition Partners, L.P. (the "PARTNERSHIP").

          Pursuant to Article XI of the Second Amended and Restated Agreement of
Limited Partnership, as amended (as so amended, the "AGREEMENT"), of the
Partnership, Prentiss Properties I, Inc. as the sole general partner of the
Partnership (the "GENERAL PARTNER"), desires to amend the Agreement to admit
Assignee as a Substitute Limited Partner with respect to the Assigned Units.

          NOW, THEREFORE, the General Partner hereby adopts the following
amendment to the Agreement.

          1.   Exhibit A to the Agreement is hereby amended and restated in its
entirety as set forth on EXHIBIT A attached hereto.

          2.   Assignee accepts and agrees to be bound by the terms and
provisions of the Agreement.

                           [Signature Page Follows]

                                       1
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          IN WITNESS WHEREOF, the General Partner and the Assignee have
executed this Tenth Amendment as of May ___, 2000.

                                   GENERAL PARTNER

                                   PRENTISS PROPERTIES I, INC.

                                        By:  /s/ MICHAEL A. ERNST
                                           ------------------------------------
                                        Name:    Michael A. Ernst
                                        Title:   Chief Financial Officer

                                   ASSIGNEE AND SUBSTITUTE LIMITED PARTNER:

                                   BELMAR REALTY CORPORATION

                                        By:  /s/ THOMAS E. FAUST, JR.
                                           ------------------------------------
                                        Name:    Thomas E. Faust, Jr.
                                        Title:   Executive Vice President

                                       2<PAGE>

                                 Exhibit 10.10

                PRENTISS PROPERTIES ACQUISITION PARTNERS, L.P.

  ELEVENTH AMENDMENT TO THE SECOND AMENDED AND RESTATED AGREEMENT OF LIMITED
         PARTNERSHIP OF PRENTISS PROPERTIES ACQUISITION PARTNERS, L.P.

                                   RECITALS

          A.   Belcrest Realty Corporation ("ASSIGNOR")desires to assign and
Belmar Realty Corporation ("ASSIGNEE") desires to acquire 365,000 8.30% Series B
Cumulative Redeemable Perpetual Preferred Units (THE "ASSIGNED UNITS") of
Prentiss Properties Acquisition Partners, L.P. (the "PARTNERSHIP").

          Pursuant to Article XI of the Second Amended and Restated Agreement of
Limited Partnership, as amended (as so amended, the "AGREEMENT"), of the
Partnership, Prentiss Properties I, Inc. as the sole general partner of the
Partnership (the "GENERAL PARTNER"), desires to amend the Agreement to admit
Assignee as a Substitute Limited Partner with respect to the Assigned Units.

          NOW, THEREFORE, the General Partner hereby adopts the following
amendment to the Agreement.

          1.   Exhibit A to the Agreement is hereby amended and restated in its
entirety as set forth on EXHIBIT A attached hereto.

          2.   Assignee accepts and agrees to be bound by the terms and
provisions of the Agreement.

                           [Signature Page Follows]

                                       1
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          IN WITNESS WHEREOF, the General Partner and the Assignee have executed
this Eleventh Amendment as of July 19, 2000.

                                   GENERAL PARTNER

                                   PRENTISS PROPERTIES I, INC.

                                        By:  /s/ MICHAEL A. ERNST
                                           ------------------------------------
                                        Name:    Michael A. Ernst
                                        Title:   Chief Financial Officer

                                   ASSIGNEE AND SUBSTITUTE LIMITED PARTNER:

                                   BELMAR REALTY CORPORATION

                                        By:  /s/ THOMAS E. FAUST, JR.
                                           ------------------------------------
                                        Name:    Thomas E. Faust, Jr.
                                        Title:   Executive Vice President

                                       2<PAGE>

                                 Exhibit 10.11

                PRENTISS PROPERTIES ACQUISITION PARTNERS, L.P.

   TWELFTH AMENDMENT TO THE SECOND AMENDED AND RESTATED AGREEMENT OF LIMITED
         PARTNERSHIP OF PRENTISS PROPERTIES ACQUISITION PARTNERS, L.P.

                                   RECITALS

          A.   Altavera Realty Corporation ("ALTAVERA") desires to assign and
Belmar Realty Corporation ("ASSIGNEE") desires to acquire 36,464 8.30% Series B
Cumulative Redeemable Perpetual Preferred Units (the "ALTAVERA UNITS") of
Prentiss Properties Acquisition Partners, L.P. (the "PARTNERSHIP").

          B.   Belair Real Estate Corporation ("BELAIR"; Altavera and Belair are
each an "ASSIGNOR" and are, collectively, the "ASSIGNORS") desires to assign and
Assignee desires to acquire 455,000 8.30% Series B Cumulative Redeemable
Perpetual Preferred Units (the "BELAIR UNITS"; the Altavera Units and the Belair
Units are, collectively, the "ASSIGNED UNITS") of the Partnership.

          Pursuant to Article XI of the Second Amended and Restated Agreement of
Limited Partnership, as amended (as so amended, the "AGREEMENT"), of the
Partnership, Prentiss Properties I, Inc. as the sole general partner of the
Partnership (the "GENERAL PARTNER"), desires to amend the Agreement to admit
Assignee as a Substitute Limited Partner with respect to the Assigned Units.

          NOW, THEREFORE, the General Partner hereby adopts the following
amendment to the Agreement.

          1.   Exhibit A to the Agreement is hereby amended and restated in its
entirety as set forth on EXHIBIT A attached hereto.

          2.   Assignee accepts and agrees to be bound by the terms and
provisions of the Agreement.

                           [Signature Page Follows]

                                       1
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          IN WITNESS WHEREOF, the General Partner and the Assignee have executed
this Twelfth Amendment as of November 29, 2000.

                                   GENERAL PARTNER

                                   PRENTISS PROPERTIES I, INC.

                                        By:  /s/ MICHAEL A. ERNST
                                           ------------------------------------
                                        Name:    Michael A. Ernst
                                        Title:   Chief Financial Officer

                                   ASSIGNEE AND SUBSTITUTE LIMITED PARTNER:

                                   BELMAR REALTY CORPORATION

                                        By:  /s/ THOMAS E. FAUST, JR.
                                           ------------------------------------
                                        Name:    Thomas E. Faust, Jr.
                                        Title:   Executive Vice President

                                       2

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