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                                                                     Exhibit 4.3

                                    FORM OF
                               EIGHTH AMENDMENT TO
                           SECOND AMENDED AND RESTATED
                        LIMITED PARTNERSHIP AGREEMENT OF
                        CORPORATE OFFICE PROPERTIES, L.P.

     THIS EIGHTH AMENDMENT (the "Amendment") to the Second Amended and Restated
Limited Partnership Agreement of Corporate Office Properties, L.P., a Delaware
limited partnership (the "Partnership"), is made and entered into as of
September 14, 2001, by and among the undersigned parties.

                                    RECITALS

     A.   The Partnership is a limited partnership organized under the
Delaware Revised Uniform Limited Partnership Act (the "Act") and governed by
that certain Second Amended and Restated Limited Partnership Agreement dated
as of January, 1999, as amended by that certain First Amendment to Second
Amended and Restated Limited Partnership Agreement dated as of December 21,
1999, that certain Second Amendment to Second Amended and Restated Limited
Partnership Agreement dated as of December 21, 1999, that certain Third
Amendment to Second Amended and Restated Limited Partnership Agreement dated
as of September 29, 2000, that certain Fourth Amendment to Second Amended and
Restated Limited Partnership Agreement dated as of November 27, 2000, that
certain Fifth Amendment to Second Amended and Restated Limited Partnership
Agreement dated as of January 25, 2001, that certain Sixth Amendment to
Second Amended and Restated Limited Partnership Agreement dated as of April
3, 2001, and that certain Seventh Amendment to Second Amended and Restated
Limited Partnership Agreement, dated as of August 30, 2001 (as amended, the
"Agreement").

     B.   The sole general partner of the Partnership is Corporate Office
Properties Trust, a real estate investment trust formed under the laws of the
State of Maryland (the "General Partner").

     C.   The General Partner has issued 1,425,000 Shares of its 9.875% Series F
Cumulative Redeemable Preferred Shares (the "Series F Preferred REIT Shares") in
a public offering (the "Offering").

     D.   As required under Sections 4.2(B) and (C) of the Agreement, the
General Partner intends to transfer the net proceeds of the Offering (or cause
them to be transferred) to or for the benefit of the Partnership in exchange for
additional Partnership Interests in the Partnership having designations, rights
and preferences substantially similar to the economic rights of the holders of
the Series F Preferred REIT Shares (the "Series F Preferred Units").

     E.   The General Partner desires to amend the Agreement to acknowledge the
contribution of the net proceeds of the Offering by the General Partner to the
Partnership in exchange for the Series F Preferred Units. Unless otherwise
defined herein, all

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capitalized terms used in this Amendment shall have the same meanings as set
forth in the Agreement.

     NOW THEREFORE, in consideration of the foregoing and of the mutual premises
set forth herein, the General Partner, intending to be legally bound hereby,
hereby amends the Agreement as follows, effective as of the date set forth
above.

     1.   The foregoing recitals to this Amendment are hereby incorporated in
and made a part of this Amendment.

          (a)  Upon consummation of the Offering, the General Partner shall
contribute the net proceeds of the Offering to the Partnership.

          (b)  Upon the contribution of the net proceeds of the Offering to the
Partnership by the General Partner, and in accordance with Section 4.2(B) of the
Agreement, the Partnership shall issue to the General Partner 1,425,000
Series F Preferred Units, equal to the number of Series F Preferred REIT Shares
issued by the General Partner in connection with the Offering.

          (c)  For purposes of the Agreement, including the maintenance of
Capital Accounts, the General Partner shall be treated as making a Capital
Contribution of $34,289,062.50, equal to the product of $24.0625 times
the number of Series F Preferred Units issued to the General Partner.

          (d)  The General Partner is hereby amending Exhibit 1 to the Agreement
by substituting for the existing addendum to EXHIBIT 1 the Addendum to EXHIBIT 1
in the form attached hereto to reflect the issuance of the Series F Preferred
Units to the General Partner.

     2.   Except as explicitly modified by this Amendment, all of the provisions
of the Agreement are hereby ratified and confirmed, and shall remain in full
force and effect.

     3.   This Amendment shall take effect upon the contribution of the net
proceeds of the Offering to the Partnership by the General Partner, and in the
event such contribution is not made, this Amendment shall be of no force or
effect.

                            (SIGNATURE PAGE FOLLOWS)

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     In witness whereof, the General Partner has executed this Amendment as of
the day and year first above written.

                                        CORPORATE OFFICE PROPERTIES TRUST,
                                        a Maryland Real Estate Investment Trust

                                        By:
                                            -----------------------------------
                                        Name:  Roger A. Waesche, Jr.
                                        Title: Senior Vice President and
                                               Chief Financial Officer

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                                    EXHIBIT 1

                                    ADDENDUM

<Table>
<Caption>

                                                   Liquidation
                                                   Preference
   Series                              No. of          Per         Priority                                    Conversion
  Preferred     Preferred Limited     Preferred     Preferred     Percentage                   Conversion     Commencement
    Units            Partner            Units         Unit         Return *       Priority       Factor           Date
  ---------     -----------------     ---------    -----------    ----------      --------     -----------    ------------
  <S>           <C>                   <C>          <C>            <C>             <C>          <C>            <C>
      A          General Partner              1        $25           1.375%        Senior        1.8748         8/28/2000
      B          General Partner      1,250,000        $25            2.50%        Senior         None             N/A
      C                UPG            1,016,662        $25             **          Senior        2.381         12/22/2000
      D          General Partner        544,000        $25            1.00%        Senior         ***              ***
      E          General Partner      1,150,000        $25          2.5625%        Senior         None             N/A
      F          General Partner      1,425,000        $25                         Senior         None             N/A
</Table>
----------

     *    Priority Return Percentage is expressed as a percentage of the
Liquidation Preference per Distribution Period. SEE the Agreement for the
definitions of "Priority Return Percentage," "Liquidation Preference" and
"Distribution Period."

     **   Priority Percentage Return for the Series C Preferred Units shall be:

          2.25% from December 21, 1999 to December 20, 2009;
          2.625% from December 21, 2009 to December 20, 2014; and
          3.00% thereafter.

          The Distribution Period for the Series C Preferred Units shall be each
calendar quarter ending March 31, June 30, September 30 and December 31 of each
year.

     ***  With respect to any series of Preferred Units issued to the General
Partner pursuant to Section 4.2(B) of the Agreement, the Conversion Commencement
Date and the applicable Conversion Factor shall correspond to the conversion
commencement date and conversion factor of the related issuance of securities by
the General Partner as provided in Section 4.2(B) of the Agreement. SEE Section
9.8(A)(1) of the Agreement.<PAGE>
                                                                     Exhibit 4.1

                              CONSULTING AGREEMENT

PARTIES

     This agreement is entered into as of September 7, 2001, by and between
Rotary Power International, Inc., a Delaware corporation with its principal
office at P.O. Box 128, Wood-Ridge, New Jersey 07075-0128 (the "Company"), and
William T. Figart, an individual residing at 11 Derby Lane, Waldwick, New Jersey
07463 (the "Consultant").

ENGAGEMENT

     The Company hereby agrees to engage the Consultant, and the Consultant, in
consideration of such engagement, hereby agrees to provide consulting services
as further described in Section 3 below.

STATEMENT OF SERVICES

     3.1. Consultant agrees that during the term of this Agreement, and any
          renewal period thereof, he will provide consulting services to the
          Company in connection with marketing and sales plans, product plans
          (engine and options descriptions), sales forecasts, pricing
          strategies, field prototype and demonstration plans, sales
          presentations, customer marketing, sales and service contacts, and
          assist in obtaining funding from Government and/or Government related
          development agencies. The days in which the Consultant shall render
          the services shall be agreed upon in advance between the Consultant
          and the Company to the extent possible.

          In addition, Consultant will provide services to develop legislative
          initiatives, and related government marketing plans, on programs of
          interest to the Company and will provide legislative liaison and
          program management support as necessary to help carry out the programs
          of the Company.

          Notwithstanding anything in this Agreement to the contrary, the
          consulting services to be rendered by Consultant in accordance with
          this Agreement shall not include any consulting services in connection
          with the offer or sale of the Company's securities in a capital
          raising transaction and do not, and will not, directly or indirectly,
          promote or maintain a market for the Company's securities.

          Consultant will work with and take guidance and directions from the
          President of the Company.

     3.2. Service provided by Consultant shall be as an independent contractor.

The term of this Agreement shall be from the date of this Agreement to December
31, 2002.

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COMPENSATION

     4.1. In consideration of the consulting services performed hereunder, the
          Company agrees to pay Consultant at rate of $50.00 per hour during
          2001 and $65.00 per hour during 2002.

     4.2. The Company agrees to reimburse Consultant for all actual business
          expenses as may be required in connection with the performance of
          services.

     4.3. The Consultant will submit invoices semimonthly for consulting
          services and expenses incurred. Expenses billed to the Company shall
          be accompanied by supporting documentation. The Company will make
          payment of these invoices from Consultant no later than 15 days from
          delivery of the invoice by the Consultant.

     4.4. The Company hereby acknowledges and agrees that (i) Consultant has
          heretofore rendered bona fide satisfactory consulting services to the
          Company, (ii) in accordance with invoices which Consultant has
          rendered to the Company for such services and which remain outstanding
          and unpaid as of the date hereof, the Company currently owes
          Consultant the amount of $17,200.20 for the services rendered during
          the months of June, July and August, 2000 to the Company, and (iii)
          the services heretofore rendered by Consultant were not in any way
          connected to or involved with the offer or sale of the Company's
          securities in a capital raising transaction and did not, directly or
          indirectly, promote or maintain a market for the Company's securities.

     4.5. In full and complete satisfaction of the amounts owed to Consultant
          and as partial consideration for Consultant entering into this
          Agreement, the Company will, as soon as possible after the date of
          this Agreement, issue and deliver 28,667 shares of the Company's
          common stock (the "Shares") to Consultant. The Shares, when issued,
          shall be registered under the Securities Act of 1933, as amended,
          pursuant to a registration statement filed by the Company with the
          Securities and Exchange Commission on Form S-8 (or, if Form S-8 is not
          then available, such other form of registration statement then
          available for the registration of the Shares). Any and all costs of
          filing such registration statement for the Shares shall be the
          responsibility of the Company.

     4.6. The Company and Consultant may at any time agree that the Company can
          issue shares of its common stock in satisfaction of any amounts that
          may hereafter become due and owing to the Consultant in accordance
          with this Agreement. The number of shares to be issued by the Company
          shall be agreed upon with Consultant in writing and any such shares,
          when issued, shall be registered under the Securities Act of 1933, as
          amended, pursuant to a registration statement filed by the Company
          with the Securities and Exchange Commission on Form S-8 (or, if Form
          S-8 is not then available, such other form of registration statement
          then available for the registration of such shares). Any and all costs
          of filing such registration statement for such shares shall be the
          responsibility of the Company.

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LIMITATIONS

     5.1. Nothing in this Agreement shall grant to either party the right to
          make commitments of any kind for or on behalf of the other party
          without prior written consent of the other party.

     5.2. Consultant represents that there is no conflict of interest between
          his performance in a consulting capacity under this Agreement and his
          relationship with other clients. If at any time in the future it is
          believed that there is a potential conflict of interest, Consultant
          will promptly so advise and the parties will mutually agree in writing
          on the resolution of this potential conflict.

     5.3. Either party may terminate this Agreement by giving ninety (90) days
          written notice of such termination.

NON-COMPETITION

     For the term of this Agreement, Consultant will not directly or indirectly,
in any capacity, without prior written approval by the Company, engage in or
render services (including, without limitation, research, development, marketing
or sales) to, or have a financial interest in, any person, Consultant,
corporation or other entity engaged in the rotary engine business.

EXEMPTION FROM COMPANY BENEFIT PLANS, POLICIES AND PROCEDURES

     The Consultant is not an employee of the Company and is, therefore, not
entitled to coverage under any of the benefit plans of the Company except as
agreed in writing by Consultant and the Company. The Consultant shall not be
bound by the policies and procedures of the Company.

FACILITIES AND SUPPORT

     The Company shall provide Consultant with office space, equipment and
support, including secretarial help, reasonably necessary to perform the tasks
which are performed on the premises of the Company. The Consultant is
responsible to provide facilities and equipment necessary outside the premises
of the Company.

CONFIDENTIAL INFORMATION

     Consultant will not disclose any trade secrets or confidential information
identified as such by the Company to any person, Consultant, corporation,
association, or other entity for any reason or purpose whatsoever, nor shall
Consultant make use of any such trade secrets or confidential information for
his own purpose or for the benefit of any person, Consultant, corporation, or
other entity, except as authorized in writing by the Company. Consultant agrees
to deliver to the Company upon termination of this Agreement, or at any other
time the Company may request, any proprietary or confidential material supplied
to the Consultant during the term of this Agreement and which the Company has
previously identified as such, relating to the business of the Company which he
may then possess or have under his control. However, there shall be no
restriction on disclosure or use of information which is publicly known other
than as a result of a breach of this Agreement, or which becomes legally
available at any time from a third party without restriction. Confidential
information obtained while

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an employee of the Company shall be specifically covered by this clause.

PROPERTY OF COMPANY

     All ideas, inventions, discoveries, proprietary information, know-how,
processes and other developments and, more specifically, improvements to
existing inventions conceived by the Consultant that were developed in relation
to performance of the Consultant's assignments for the Company, shall be the
property of the Company. Consultant shall execute all documents, including
patent applications and assignments, required by the Company to establish the
Company's rights under this paragraph.

MISCELLANEOUS

     NOTICES: All notices pertaining to this Agreement shall be in writing and
shall be transmitted either by personal hand delivery or through the facilities
of the United States Postal Service, certified or registered mail, return
receipt requested. The addresses set forth in the first paragraph of this
Agreement for the respective parties shall be the places where notices shall be
sent, unless written notice of a change of address is given. Notices shall be
deemed to have been given at the time of delivery if transmission is by personal
hand delivery or, if mail, forty-eight (48) hours after deposited in a regularly
maintained receptacle of the United States Postal Service for mailing as
aforesaid.

     CAPTION HEADINGS: Captions at the beginning of each numbered paragraph of
this Agreement are solely for the convenience of the parties and shall not be
deemed part of the context of this Agreement.

     ENTIRE AGREEMENT: This Agreement contains the entire Agreement between the
parties hereto, and supersedes any written or oral agreement between the parties
concerning the subject matter contained herein. There are no representations,
agreements, arrangement or understandings, oral or written, between or among the
parties hereto, relating to the subject matter contained in this Agreement,
which are not fully expressed herein.

     AMENDMENT: This Agreement may only be amended by the written consent of
both parties at the time of such amendment.

     GOVERNING LAW: The validity, interpretation, construction and performance
of this Agreement shall be controlled by and construed under the laws of the
State of New Jersey. In the event of any litigation arising out of any dispute
in connection with this Agreement, the Company and Consultant hereby consent to
the jurisdiction of the New Jersey courts.

     COUNTERPARTS: This Agreement may be executed in counterparts, each of which
shall be deemed to be an original, but such counterparts, when taken together,
shall constitute but one agreement.

     SEVERABILITY: In the event any provision of this Agreement is held to be
invalid, void or unenforceable, the rest of the provisions shall, nonetheless,
remain in full force and effect and shall in no way be affected, impaired or
invalidated.

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RENEWAL

     The parties may renew this Agreement at any time by written instruments
signed by the parties. It is anticipated that each such renewal shall be upon
the same terms and conditions as herein provided, except for necessary changes
in dates, scope of work, or total compensation.

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the day and year first above written.

WILLIAM T. FIGART                           ROTARY POWER INTERNATIONAL, INC.

By: /s/ William T. Figart                   By:  /s/ Ronald G. McKeown
    ---------------------------                  ----------------------------
                                                 Name:  Ronald G. McKeown
                                                 Title: President and CEO

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