Document:

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                                                                    Exhibit 10.3

                                    GUARANTY

                  THIS GUARANTY ("GUARANTY"), dated as of December 13, 1999, is
made by PRIME GROUP REALTY, L.P., a Delaware limited partnership, having an
address at c/o Prime Group Realty Trust, 77 West Wacker Drive, Chicago, Illinois
60601 ("GUARANTOR"), in favor of WESTDEUTSCHE IMMOBILIENBANK, a German banking
corporation ("LENDER"), whose address is Wil.-Th.-Roemheld-Str. 24, 55130 Mainz,
Germany, and is executed pursuant to the Loan Agreement, dated as of the date of
this Guaranty, by and between 330 N. Wabash Avenue, L.L.C., a Delaware limited
liability company (the "BORROWER") and Lender (hereinafter referred to as
"AGENT") for itself and Merrill Lynch Mortgage Capital Inc., a Delaware
corporation and such other co-lenders as may exist from time to time
(collectively with Agent, "LENDERS" and each individually, "LENDER") under the
Loan Agreement (such Loan Agreement, as it may from time to time be
supplemented, modified and amended in accordance with the terms thereof, being
referred to in this Guaranty as the "LOAN AGREEMENT"; capitalized terms used but
not defined herein but defined in the Loan Agreement shall have the meanings
assigned to them in the Loan Agreement), the provisions of which are
incorporated in this Guaranty by reference. The Loan Agreement provides, among
other things, for rules of construction which apply to this Guaranty.

                              W I T N E S S E T H:

                  WHEREAS, the Borrower, Agent and Lender have entered into the
Loan Agreement;

                  WHEREAS, Guarantor will derive substantial direct and indirect
benefit from the transactions contemplated by the Loan Documents; and

                  WHEREAS, the Agent is unwilling to make the loan pursuant to
the Loan Documents unless it receives a guaranty by Guarantor for the benefit of
Agent and Lender of the Guarantied Obligations (as hereinafter defined);

                  NOW, THEREFORE, in consideration of the recitals set forth
above and incorporated herein, the agreements contained herein and other good
and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, and to induce the Agent to accept the Loan Documents as aforesaid
and make the Loan, Guarantor hereby covenants and agrees as follows:

                  1. GUARANTIED OBLIGATIONS. (a) Commencing as of the first
(1st) anniversary of the funding of the Loan and subject to the provisions of
subsection (b) below, Guarantor unconditionally, absolutely and irrevocably, as
a primary obligor and not merely as a surety, guaranties to Agent the full and
punctual payment and performance of the following in accordance with the Loan
Documents (the "GUARANTIED OBLIGATIONS"): (i) in the event that the Debt Service
Coverage Ratio shall be less than 1.3:1 on a Debt Service Coverage Ratio
Calculation Date, the repayment of the first twenty percent (20%) of the
principal balance of the Loan outstanding as of the applicable Debt Service
Coverage Ratio Calculation Date; (ii) in the event that the Debt Service
Coverage Ratio is equal to or greater than 1.3:1, but less than 1.5:1 on a Debt
Service Coverage Ratio Calculation Date, the repayment of a portion of the
principal balance of the Loan outstanding as of the applicable Debt Service
Coverage Ratio Calculation Date equal to the difference between (A) the amount
of the loan outstanding as of the applicable Debt Service Coverage Ratio
Calculation Date and (B) One Hundred Thirty Five Million Dollars
($135,000,000.00); (iii) the payment and performance of all obligations under
Section 6.1(l) of the Loan Agreement; and (iv) the payment and performance of
all obligations under Section 6.1(m) of the Loan Agreement.

                  (b) In the event that the conditions set forth in subsection
(a)(i) or (ii) above shall occur, Guarantor shall only be obligated to guaranty
the Guarantied Obligations described in such subsections (a)(i) or (ii) as
applicable until, subject to future reinstatement of such Guarantied
Obligations, a Debt Service Coverage Ratio of 1.5:1 or greater is achieved for
two (2) consecutive calendar quarters. Nothing in this Section 1(b) shall limit
the Guaranteed Obligations set forth in Sections 1(a)(iii) and (iv) above.

                  (c) For the purpose of this Guaranty, the Debt Service
Coverage Ratio shall be calculated initially on the first anniversary of the
funding of the Loan, and thereafter at the end of each quarter (each, a "DEBT
SERVICE CALCULATION RATIO CALCULATION DATE").

                  2. GUARANTY ABSOLUTE. (a) Guarantor guarantees that the
Guarantied Obligations will be paid strictly in accordance with the Loan
Documents, regardless of any law, statute, rule, regulation, decree or order now
or hereafter in effect in any jurisdiction affecting or purporting to affect in
any manner any of such terms or the rights or remedies of Agent with respect
thereto.

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                  (b) Any payment or payments made by the Borrower or any other
person or received or collected by Agent from Borrower or any other person by
virtue of any action or proceeding or any other set-off or appropriation or
application at any time or from time to time in respect of any indebtedness,
obligations or liabilities of Borrower under the Loan Documents may be applied
by the Agent in satisfaction of such indebtedness, obligations and liabilities
in such order as Agent may determine, subject to the terms of the Loan
Documents, and no application of such payment or payments to satisfaction of
indebtedness, obligations or liabilities other than the Guarantied Obligations
shall discharge in any manner any obligations of the Guarantor hereunder.

                  (c) The liability of Guarantor under this Guaranty shall be
absolute and unconditional, and shall not be affected, released, terminated,
discharged or impaired, in whole or in part, by, and Agent may proceed to
exercise any right or remedy hereunder irrespective of, any or all of the
following:

                  (i) any lack of genuineness, regularity, validity, legality or
         enforceability, or the voidability of, all or any of the Loan Documents
         or any other agreement or instrument relating thereto;

                  (ii) the failure of Agent to exercise or to exhaust any right
         or remedy or take any action against Borrower or any collateral or
         other security available to it;

                  (iii) any amendment or modification of the terms of any or all
         of the Loan Documents;

                  (iv) any change in the time, manner or place of payment, of
         all or any of the Guarantied Obligations or any extensions of time for
         payment, whether in whole or in part, of the terms of any or all of the
         Loan Documents on the part of Borrower to be paid;

                  (v) any amendment or waiver of, or any assertion or
         enforcement or failure or refusal to assert or enforce, or any consent
         or indulgence granted by Agent with respect to a departure from, any
         term of any of the Loan Documents, including, without limiting the
         generality of the foregoing, the waiver by Agent of any default of
         Borrower, or the making of any other arrangement with, or the accepting
         of any compensation or settlement from, Borrower;

                  (vi) any failure or delay of Agent to exercise, or any lack of
         diligence in exercising, any right or remedy with respect to the Loan
         Documents or this Guaranty;

                  (vii) any dealings or transactions between Agent and Borrower,
         whether or not Guarantor shall be a party to or cognizant of the same;

                  (viii) any bankruptcy, insolvency, assignment for the benefit
         of creditors, receivership, trusteeship or dissolution of or affecting
         Borrower;

                  (ix) any exchange, surrender or release, in whole or in part,
         of any security which may be held by Agent at any time for or under the
         Loan Documents or in respect of the Guarantied Obligations;

                  (x) any other guaranty now or hereafter executed by Guarantor
         or any other guarantor or the release of any other guarantor from
         liability for the payment, performance or observance of any of the
         Guarantied Obligations or any of the terms of the Loan Documents on the
         part of Borrower to be paid, whether by operation of law or otherwise;

                  (xi) any rights, powers or privileges Agent may now or
         hereafter have against any person, entity or collateral in respect of
         the Guarantied Obligations;

                  (xii) Agent's consent to any assignment or successive
         assignments of the Loan Documents by Borrower;

                  (xiii) any other circumstance which might in any manner or to
         any extent constitute a defense available to Borrower, or vary the risk
         of Guarantor, or might otherwise constitute a legal or equitable
         discharge or defense available to a surety or guarantor, whether
         similar or dissimilar to the foregoing;

                  (xiv) any and all notice of the creation, renewal or extension
         of the Guarantied Obligations and notice of or proof of reliance by
         Agent upon this Guaranty or acceptance of the Guaranty; or

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                  (xv) any change, restructuring or termination of the
         organizational structure or existence of the Borrower;

whether occurring before or after any default by Borrower under the Loan
Documents, and with or without further notice to or assent from Guarantor.

                  (d) This Guaranty shall continue to be effective or be
reinstated, as the case may be, and the rights of Agent hereunder shall continue
with respect to, any Obligation (or portion thereof) at any time paid by
Borrower which shall thereafter be required to be restored or returned by Agent
upon the insolvency, bankruptcy or reorganization of Borrower, or for any other
reason, all as though such Obligation (or portion thereof) had not been so paid
or applied.

                  (e) Notwithstanding anything to the contrary contained herein,
the obligations of Guarantor hereunder shall survive the maturity, satisfaction
or assignment of the Mortgage (as defined in the Loan Documents), or foreclosure
of the Mortgage or delivery of a deed in lieu thereof; PROVIDED, HOWEVER, if the
Mortgage is satisfied and the Loan repaid in full, the Guaranty shall terminate.

                  3. REPRESENTATIONS AND WARRANTIES. Guarantor represents and
warrants, as of the date hereof, to Agent as follows:

                  (a) Guarantor is a duly organized, validly existing limited
partnership and in good standing under the laws of Delaware, and has full
power, authority and legal right to execute and deliver this Guaranty and to
perform fully and completely all of its obligations hereunder.

                  (b) The execution, delivery and performance of this
Guaranty by Guarantor has been duly authorized by all necessary action, and,
will not violate any provision of any law, regulation, order or decree of any
governmental authority, bureau or agency or of any court binding on Guarantor,
or any provision of the limited partnership agreement of Guarantor, or of any
contract, undertaking or agreement to which Guarantor is a party or which is
binding upon Guarantor or any of its property or assets, and will not result
in the imposition or creation of any lien, charge or encumbrance on, or
security interest in, any of its property or assets pursuant to the provisions
of any of the  foregoing.

                  (c) This Guaranty has been duly executed and delivered by a
duly authorized officer of the managing general partner of Guarantor and
constitutes a legal, valid and binding obligation of Guarantor, enforceable
against it in accordance with its terms, subject as to enforcement of remedies
to any applicable bankruptcy, reorganization, moratorium or other laws
affecting the enforcement of creditors' rights generally and doctrines
of equity affecting the availability of specific enforcement as a remedy.

                  (d) All necessary resolutions, consents, licenses, approvals
and authorizations of any person or entity required in connection with the
execution, delivery and performance of this Guaranty have been duly obtained
and are in full force and effect.

                  (e) There are no conditions precedent to the effectiveness of
this Guaranty that have not been either satisfied or waived.

                  (f) The Guarantor has, independently and without reliance upon
the Agent and based on such documents and information as it has deemed
appropriate, made its own credit analysis and decision to enter into this
Guaranty.

                  (g) Guarantor is the holder, directly or indirectly, of 100%
of the beneficial interests of Borrower and until the Guarantied Obligations
have been fully paid and performed, Guarantor shall continue to hold at least
fifty percent (50%) of the beneficial interests in Borrower.

                  4. WAIVERS. Guarantor expressly waives the following:

                  (a) notice of acceptance of this Guaranty and of any change in
the financial condition of Borrower;

                  (b) promptness, diligence, presentment and demand for payment
of any of the Guarantied Obligations;

                  (c) protest, notice of dishonor, notice of default and any
other notice with respect to any of the Guarantied Obligations and/or this
Guaranty;

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                  (d) any demand for payment under this Guaranty;

                  (e) the right to interpose all substantive and procedural
defenses of the law of guaranty, indemnification and suretyship, except the
defenses of prior payment by Borrower of the Guarantied Obligations which
Guarantor is called upon to pay under this Guaranty;

                  (f) all rights and remedies accorded by applicable law to
guarantors, or sureties, including, without being limited to, any extension of
time conferred by any law now or hereafter in effect;

                  (g) the right to trial by jury in any action or proceeding of
any kind arising on, under, out of, or by reason of or relating, in any way, to
this Guaranty or the interpretation, breach or enforcement hereof;

                  (h) the right to interpose any setoff or counterclaim of any
nature or description in any action or proceeding arising hereunder or with
respect to this Guaranty;

                  (i) any right or claim of right to cause a marshalling of the
assets of Borrower or to cause Agent to proceed against Borrower and/or any
collateral or security held by Agent at any time or in any particular order;

                  (j) any defense based on any statutory or other limitation of
the amount of any deficiency judgment available to Agent after foreclosure or
other proceedings to realize upon any collateral security; and

                  (k) any defense or benefits that may be afforded by Section
1301 of the New York Real Property Actions and Proceedings Law or any statute or
law in any other jurisdiction having similar effect.

                  (l) any defense based on the failure to make Guarantor a
defendant in any action to foreclose the Mortgage.

                  5. BANKRUPTCY. Notwithstanding anything to the contrary
herein, Guarantor's liability shall extend to all amounts which constitute part
of the Guarantied Obligations and would be owed by Borrower under the Loan
Documents but for the fact that they are unenforceable or not allowable due to
the existence of a bankruptcy, reorganization or similar proceeding involving
Borrower. Without limiting the foregoing, neither Guarantor's obligation to make
payment in accordance with this Guaranty nor any remedy for the enforcement
thereof shall be impaired, modified, changed, stayed, released or limited in any
manner by any impairment, modification, change, release, limitation or stay of
the liability of Borrower or its estate in bankruptcy or any remedy for the
enforcement thereof, resulting from the operation of any present of future
provision of the Bankruptcy Code or other statute or from the decision of any
court interpreting any of the same.

                  6. CURRENCY OF PAYMENTS. Any and all amounts required to be
paid by Guarantor hereunder shall be paid in lawful money of the United States
of America and in immediately available funds to Agent. Guarantor agrees that
whenever, at any time, or from time to time, it shall make any payment to Agent
on account of its liability hereunder, it will notify Agent in writing that such
payment is made under this Guaranty for that purpose.

                  7. WAIVER OF RIGHTS AGAINST BORROWER; SUBORDINATION. (a) Until
such time as the Loan is paid in full, Guarantor hereby irrevocably waives all
rights of subrogation and any other claims that it may now or hereafter acquire
against either Borrower or any insider that arise from the existence, payment,
performance or enforcement of Guarantor's obligations under this Guaranty or any
other documents executed in connection herewith (collectively, the "GUARANTY
DOCUMENTS"), including, without limitation, any right of reimbursement,
exoneration, contribution or indemnification and any right to participate in any
claim or remedy of Agent against either Borrower or any insider, whether or not
such claim, remedy or right arises in equity or under contract, statute or
common law, including, without limitation, the right to take or receive from
either Borrower or any insider, directly or indirectly, in cash or other
property or by set-off or in any other manner, payment or security on account of
such claim, remedy or right.

                  (b) If any amount shall be paid to Guarantor in violation of
the preceding subsection (a) at any time prior to the indefeasible cash payment
in full of all amounts payable under this Guaranty, such amount shall be held in
trust for the benefit of Agent and shall forthwith be paid to Agent to be
credited and

<PAGE>

applied to all amounts payable under this Guaranty, whether matured or
unmatured, in accordance with the terms of the Loan Documents and the Guaranty
Documents, or to be held as collateral for any amounts payable under this
Guaranty thereafter arising. Guarantor acknowledges that it has and will receive
direct and indirect benefits from the financing arrangements contemplated by the
Loan Documents and the Guaranty Documents and that the waiver set forth in this
subsection is knowingly made in contemplation of such benefits.

                  (c) All indebtedness, liabilities and obligations of Borrower
to Guarantor, whether secured or unsecured and whether or not evidenced by any
instrument, now existing or hereafter created or incurred, are and shall be
subordinate and junior in right of payment to the Guarantied Obligations.

                  8. AMENDMENT IN WRITING. No amendment or waiver of any
provision of this Guaranty nor consent to any departure by Guarantor therefrom
shall in any event be effective unless the same shall be in writing and signed
by Agent and Guarantor, and then such waiver or consent shall be effective only
in the specific instance and for the specific purpose for which given.

                  9. REMEDIES. The obligations of Guarantor under this Guaranty
are independent of the Borrower's obligations under the Loan Documents, and a
separate action or actions may be brought and prosecuted against the Guarantor
to enforce this Guaranty, irrespective of whether any action is brought against
the Borrower or whether the Borrower is joined in any such action or actions.
Any one or more successive and/or concurrent actions may be brought hereon
against Guarantor either in the same action, if any, brought against Borrower or
in separate actions, as often as Agent, in its sole discretion, may deem
advisable.

                  10. CERTIFIED STATEMENT. Guarantor agrees that it will, at any
time and from time to time, within twenty (20) days following request by Agent,
execute and deliver to Agent a statement certifying that this Guaranty is
unmodified and in full force and effect (or if modified, that the same is in
full force and effect as modified and stating such modifications).

                  11. NOTICES. Unless expressly contained herein, all notices
given hereunder shall be given in accordance with the terms of the Mortgage. All
such notices and other communications shall be effective 2 business days after
deposited in the mails addressed as aforesaid.

                  12. CONTINUING GUARANTY; SUCCESSORS AND ASSIGNS. This Guaranty
is a continuing guaranty and shall (i) remain in full force and effect until (a)
payment, performance and/or observance in full of the Guarantied Obligations and
all other amounts payable under this Guaranty and (b) repayment of the Loan,
(ii) be binding upon Guarantor, its successors and assigns, and (iii) inure to
the benefit of and be enforceable by Agent and its successors, transferees and
assigns or by any person to whom Agent's interest in the Loan Documents may be
assigned. Wherever in this Guaranty reference is made to Agent or Borrower, the
same shall be deemed to refer also to the then successor or assign of Agent or
Borrower.

                  13. GOVERNING LAW. This Guaranty shall be governed by, and
construed in accordance with, the laws of the State of New York applicable to
agreements made and to be performed entirely within said state.

                  14. SEVERABILITY. If any term, covenant, condition or
provision of this Guaranty or the application thereof to any circumstance or to
Guarantor shall be invalid or unenforceable to any extent, the remaining terms,
covenants, conditions and provisions of this Guaranty or the application thereof
to any circumstances or to Guarantor other than those as to which any term,
covenant, condition or provision is held invalid or unenforceable, shall not be
affected thereby and each remaining term, covenant, condition and provision of
each, shall not be affected thereby and each remaining term, covenant, condition
and provision of this Guaranty shall be valid and shall be enforceable to the
fullest extent permitted by law.

                  15. NONRECOURSE OBLIGATIONS. The Loan Documents contain
provisions which limit Agent's remedies against Borrower upon a default to an
action of foreclosure and realization upon the collateral encumbered by the Loan
Documents and prohibit any action to recover a deficiency judgment against
Borrower following such foreclosure and realization. None of the foregoing
provisions shall be construed to abrogate or limit the obligations of Guarantor
and this Guaranty.

                  16. INSTRUMENT FOR PAYMENT OF MONEY ONLY. Guarantor hereby
agrees and acknowledges that this Guaranty is an instrument for the payment of
money only and hereby consents that Agent, at its sole option, in the event of a
default by Guarantor in the payment of any of the amounts payable by Guarantor
hereunder, shall have the right to bring a motion or action under New York CPLR
Section 3213.

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                  17. ANNUAL AUDITED FINANCIAL STATEMENTS. Guarantor hereby
agrees to provide Agent with annual financial statements of the Guarantor
certified by an officer having the status of senior vice-president or above
within one hundred twenty (120) calendar days of the end of each calendar year
during the Term of the Loan.

                  18. LIABILITY OF GUARANTOR. Liability under this Guaranty
shall be limited to the Guarantor and shall not extend to any direct or indirect
partner, member, shareholder, principal, director, employee, officer or
affiliate of Guarantor.

                  19. HEADINGS. The headings used in this Guaranty are for
convenience only and are not to be considered in connection with the
interpretation or construction of this Guaranty.

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                  IN WITNESS WHEREOF, Guarantor has executed and delivered this
Guaranty as of the date first above written.

                                           GUARANTOR

                                           PRIME GROUP REALTY, L.P.
                                           By: Prime Group Realty Trust, its
                                           Managing General Partner

                                           BY:
                                           Jeffrey A. Patterson
                                           Executive Vice President<PAGE>

                                                                    Exhibit 10.4

                      SEVENTH AMENDMENT TO CREDIT AGREEMENT

         This Seventh Amendment to Credit Agreement is made as of the 22nd day
of October, 1999 by and among PRIME GROUP REALTY, L.P., a Delaware limited
partnership (the "Borrower"), PRIME GROUP REALTY TRUST, a Maryland trust (the
"Company") and BANKBOSTON, N.A., a national banking association ("BankBoston"),
CIBC INC., a Delaware corporation ("CIBC"), PRUDENTIAL SECURITIES CREDIT
CORPORATION, a Delaware corporation ("Prudential"), the other lending
institutions which are from time to time listed on Schedule 1, (collectively,
with BankBoston and CIBC, the "Lenders") and BANKBOSTON, N.A., as agent for
itself and such other lending institutions (the "Agent").

         WHEREAS, the parties hereto are parties to that certain Credit
Agreement dated as of November 17, 1997 as amended by First Amendment to Credit
Agreement dated as of December 15, 1997 and by Second Amendment to Credit
Agreement dated as of March 16, 1998, as amended and restated by Third Amendment
to Credit Agreement dated as of March 30, 1998 as amended by Fourth Amendment to
Credit Agreement dated as of April 24, 1998, as amended by Fifth Amendment to
Credit Agreement dated as of October 1, 1998 and as amended and restated by
Sixth Amendment to Credit Agreement dated as of February 4, 1999 (the "Existing
Agreement"); and

         WHEREAS, the parties have agreed to amend the Existing Agreement so as
to decrease the Total Commitment and to effect certain other changes in the
Existing Agreement.

         NOW, THEREFORE, the parties hereby agree that effective upon the
Effective Date hereof (as determined pursuant to Paragraph 18 below) the
Existing Agreement is amended as follows, provided that the amended definition
of EBITDA set forth herein shall be used for all Compliance Certificates
delivered after the Effective Date, even though said Compliance Certificates may
relate to periods prior to the Effective Date:

         1. DECREASE IN TOTAL COMMITMENT. The Total Commitment is hereby
decreased to $35,000,000 and each Lender hereby decreases its Commitment to the
amount shown on the revised Schedule 1.2 attached hereto. As of the Effective
Date the Commitment Percentages of the Lenders shall be adjusted as shown on
said revised Schedule 1.2. Prudential, which is shown on such revised Schedule
1.2 as having a zero Commitment and 0% Commitment Percentage shall no longer be
a Lender hereunder after the Effective Date.

         2. DEFINITIONS: Section 1.1 of the Existing Agreement is amended to
provide that the following terms shall have the following meanings and, to the
extent that any of the following terms are already defined in the Existing
Agreement, such definitions shall be deemed to be amended and restated by the
following definitions:

         EBITDA. The Borrower's earnings before interest, taxes, depreciation
and amortization, excluding therefrom any gains or losses realized upon the
disposition of assets and other nonrecurring or extraordinary items, all as
determined on a consolidated basis in accordance with Generally Accepted
Accounting Principles, except that rental income shall be determined based on
contractual lease terms (to the extent that the applicable tenant is actually
paying rent in

<PAGE>

accordance with such terms). To the extent not already included in the Company's
EBITDA pursuant to the equity basis of accounting for the Unconsolidated
Entities, EBITDA shall also include the Unconsolidated Entity Percentage of the
earnings before interest, taxes, depreciation and amortization, excluding
therefrom any gains or losses realized upon the disposition of assets and other
nonrecurring or extraordinary items, with respect to each of the Unconsolidated
Entities.

         3. AMENDMENT TO Section 7.23. Section 7.23 is hereby amended and
restated to read as follows:

         Section 7.23. Amendments of Documents for other Recourse Indebtedness.
On or before December 31, 1999, Borrower shall deliver to the Agent copies of
amendments to each of the loan documents for the Borrower's Recourse
Indebtedness, including the Lasalle National Bank $15,000,000 line of credit and
the Bank One, Illinois $48,809,587 letter of credit facilities (unless such
facilities have been terminated prior to such time), as necessary to permanently
modify any leverage covenants and related definitions contained therein so that
such covenants are not more stringent than the 65% ratio set forth in Section
9.3 hereof, and so that such leverage covenants are calculated in the same
manner as provided in this Agreement as amended.

         4. AMENDMENT TO Section 14.12. Section 14.12 is hereby amended by
changing the Commitment amount set forth therein from $20,000,000 to
$10,000,000.

         5. UPDATED SCHEDULES TO CREDIT AGREEMENT. The following Schedules to
the Credit Agreement are hereby updated, supplemented or replaced as follows:

         (a)      Schedule 1 is replaced by Schedule 1 attached hereto.

         (b)      Schedule 1.1 is replaced by Schedule 1.1 attached hereto.

         (c)      Schedule 1.2 is replaced by Schedule 1.2 attached hereto.

         (d)      Schedule 1.3 is replaced by Schedule 1.3 attached hereto.

         (e)      Schedule 8.1(f) is replaced by Schedule 8.1(f) attached
                  hereto.

         6. REPRESENTATIONS AND WARRANTIES. The Borrower and the Company
represent and warrant that each of the representations and warranties contained
in Section 6 is true, correct and complete in all material respects as of the
date hereof to the same extent as though made on such date and that no Default
or Event of Default has occurred and is continuing on the date hereof.

         7. EFFECTIVENESS OF LOAN DOCUMENTS. The Borrower hereby confirms that
each of the Security Documents shall continue to secure the payment and
performance of all of the Obligations under the Existing Agreement as amended
hereby and the Borrower's obligations under the Security Documents shall
continue to be valid and enforceable and shall not be impaired or limited by the
execution or effectiveness of this Amendment. Every reference contained in the
Loan Documents to the Credit Agreement shall mean and be a reference to the
Existing Agreement as amended hereby and as the Credit Agreement may be further
amended.

                                       2
<PAGE>

Except as specifically amended by this Amendment, the Existing Agreement and
each of the Loan Documents shall remain in full force and effect and are hereby
ratified and confirmed.

         8. MISCELLANEOUS. This Amendment shall be governed by, interpreted and
construed in accordance with all of the same provisions applicable under the
Existing Agreement including, without limitation, all definitions set forth in
Section 1.1, the rules of interpretation set forth in Section 1.2, the
provisions relating to governing law set forth in Section 20, the provisions
relating to counterparts in Section 22 and the provision relating to
severability in Section 26.

         9. CONDITIONS TO EFFECTIVENESS. This Seventh Amendment to Credit
Agreement shall become effective on the earliest date (the "Effective Date")
that each of the following conditions precedent have been satisfied:

         (a) Documents . Each of (i) this Seventh Amendment to Credit Agreement,
(ii) the Seventh Amendment to the Guaranty, and (iii) replacement Loan Notes for
the Lenders reflecting the amount of their Commitments as reduced pursuant
hereto shall have been duly executed and delivered by the respective parties
thereto, shall be in full force and effect and shall be in form and substance
satisfactory to each of the Lenders.

         (b) Certified Copies of Amendments of Organization Documents . The
Agent shall have received a Certificate of the Company to which there shall be
attached complete copies of any amendments to the Borrower's Limited Partnership
Agreement, Borrower's Certificate of Limited Partnership the Company's
Declaration of Trust or the Company's Bylaws which have become effective since
the complete certified copies of such documents which were previously delivered
to the Agent.

         (c) Resolutions . All action on the part of the Borrower and each
Guarantor necessary for the valid execution, delivery and performance by the
Borrower and each Guarantor of this Amendment and the Seventh Amendment to the
Guaranty shall have been duly and effectively taken, and evidence thereof
satisfactory to the Agent shall have been provided to the Agent. The Agent shall
have received from the Company true copies of the resolutions adopted by its
Board of Directors authorizing the transactions described herein, certified by
its secretary to be true and complete and in effect on the Effective Date.

         (d) Opinions of Counsel . Each of the Lenders and the Agent shall have
received favorable opinions addressed to the Lenders and the Agent and dated as
of the Effective Date, substantially in the same form as, or with appropriate
provisions incorporating by reference, the opinions from Borrower's counsel
previously delivered to the Lenders and the Agent, copies of which are attached
as Exhibit E to the Credit Agreement. Such opinion may rely on opinions from
other law firms approved by the Agent as to matters of law applicable in the
various states.

         In the event that the Effective Date has not occurred on or before
October 29, 1999, then this instrument shall be void and the Existing Agreement
shall remain in effect as though this instrument had never been executed.

                                       3
<PAGE>

         IN WITNESS WHEREOF, the undersigned have duly executed this Amendment
as a sealed instrument as of the date first set forth above.

                                       PRIME GROUP REALTY TRUST

                                       By: /s/ Louis G. Conforti
                                           ----------------------------
                                           Louis G. Conforti

                                          Its: Executive Vice President

                                       PRIME GROUP REALTY, L.P.
                                       By: PRIME GROUP REALTY TRUST,
                                           its managing general partner

                                       By: /s/ Louis G. Conforti
                                           ----------------------------
                                           Louis G. Conforti

                                          Its: Executive Vice President

                                       BANKBOSTON, N.A.,, as Agent

                                       By: /s/ Lori Y. Litow
                                           ----------------------------
                                           Lori Y. Litow

                                          Its: Vice President

                                       4
<PAGE>

WITNESS:                                    BANKBOSTON, N.A.

Angela M. Collins                           By: /s/ Lori Y. Litow
                                                -----------------------
                                                Lori Y. Litow
                                                Its Vice President

Commitment:                                                        $17,500,000

Commitment Percentage:                                             50%

Notice Address:                             BankBoston, N.A.
                                            100 Federal Street
                                            Boston, MA  02110
                                            Attn: Real Estate Department

                                            With a copy to:

                                            BankBoston, N.A.
                                            115 Perimeter Center Place, N.E.
                                            Suite 500
                                            Atlanta, GA 30346
                                            Attn: Lori Y. Litow, Vice President

                                            Fax:     (770)390-8434 or 391-9811

                                       5
<PAGE>

WITNESS:                                    CIBC  INC.

______________________________              By: /s/ Joel Gershkon
                                                ------------------------
                                                Joel Gershkon

Commitment:                                                       $17,500,000

Commitment Percentage:                                            50%

Notice Address:

         CIBC Inc.
         c/o CIBC World Markets Corp.
         200 West Madison Street, Suite 2300
         Chicago, Illinois 60606
         Attn: Joel Gershkon, Executive Director

         Phone:   (312)855-3243
         Fax:     (312)855-3235

with a copy to:

         CIBC Inc.
         c/o CIBC World Markets Corp.
         2 Paces West
         2727 Paces Ferry Road, Suite 1200
         Atlanta, Georgia 30326
         Attn: Beverly Bowman

         Phone: (770) 319-4824
         Fax:   (770) 319-4950

                                       6
<PAGE>

WITNESS:                                    PRUDENTIAL SECURITIES
                                            CREDIT CORPORATION

/s/ Michael Pierro                          By: /s/ Jeffrey K. French
------------------------------                  -------------------------
Michael Pierro                                  Jeffrey K. French

Commitment:                                                        $0

Commitment Percentage:                                             0%

Notice Address:

         Prudential Securities Credit Corporation
         One New York Plaza
         New York, New York  10292  .
         Attn: Fuller O'Connor, Director

         Phone:   (212)778-3720
         Fax:     (212)778-3194 or 2253

                                       7
<PAGE>

                                   SCHEDULE 1

                LENDERS; DOMESTIC AND EURODOLLAR LENDING OFFICES

<TABLE>
<CAPTION>
DOMESTIC AND EURODOLLAR LENDING OFFICES:             NOTICE ADDRESS:
<S>                                                  <C>
BankBoston, N.A.                                     BankBoston, N.A.
100 Federal Street                                   100 Federal Street
Boston, MA  02110                                    Boston, MA  02110
(Domestic and Eurodollar)                            Attn: Real Estate Department

                                                     With a copy to:

                                                     BankBoston, N.A.
                                                     115 Perimeter Center Place, N.E.
                                                     Suite 500
                                                     Atlanta, GA  30346
                                                     Attn: Lori Y. Litow, Vice President
                                                     Fax:  (770) 390-8434 or 391-9811

CIBC Inc.                                            CIBC Inc.
c/o CIBC World Markets Corp.                         c/o CIBC World Markets Corp.
200 West Madison Street, Suite 2300                  200 West Madison Street, Suite 2300
Chicago, Illinois 60606                              Chicago, Illinois 60606
(Domestic and Eurodollar)

                                                     Attn: Joel Gershkon, Executive Director
                                                     Phone: (312)855-3243
                                                     Fax: (312)855-3235

                                                     with a copy to:
                                                     CIBC Inc.
                                                     c/o CIBC World Markets Corp.
                                                     2 Paces West
                                                     2727 Paces Ferry Road, Suite 1200
                                                     Atlanta, Georgia 30326

                                                     Attn: Beverly Bowman
                                                     Phone: (770) 319-4824
                                                     Fax:   (770) 319-4950
</TABLE>

                                       8
<PAGE>

                                  SCHEDULE 1.1

<TABLE>
<CAPTION>
         MORTGAGED PROPERTIES                                           FEE OWNER
         --------------------                                           ---------
<S>                                                           <C>
1.       Hilton Parking Garage, Knoxville, TN                 Triad Parking Company, Ltd.

2.       SunTrust Bank Bldg., 201 4th Ave., N.,
         Nashville, TN                                        Nashville Office Building I, Ltd.

3.       The Weston, 4823 Kingston Pike,
         Knoxville, TN                                        Old Kingston Properties, Ltd.

4.       One Centre Square, 620 Market St.,
         Knoxville, TN                                        Professional Plaza, Ltd.

5.       Two Centre Square, 625 Gay St.,
         Knoxville, TN                                        Centre Square II, Ltd.

6.       Salt Creek Office Center and Sun Annex,              1990 Algonquin Road, L.L.C.
         1990-2060 Algonquin Road, Schaumburg, IL             2010 Algonquin Road, L.L.C.

7.       Enterprise Drive Office Center,
         2205-2255  Enterprise Drive, Westchester, IL         Enterprise Drive, L.L.C.

8.       4849-4851 Groveport Pike, Obetz, Ohio                Prime Columbus Industrial, L.L.C.

9.       2160 McGaw Road, Obetz, Ohio                         Prime Columbus Industrial, L.L.C.

10.      2400-2410 McGaw Road, Obetz, Ohio                    Prime Columbus Industrial, L.L.C.

11.      5160-5168 Paul G. Blazer Memorial Parkway,           Prime Columbus Industrial, L.L.C.
         Dublin, Ohio

12.      600 London Road, Delaware, Ohio                      Prime Columbus Industrial, L.L.C.
</TABLE>

                                        8
<PAGE>

                                  SCHEDULE 1.2

                                   COMMITMENTS

<TABLE>
<CAPTION>
------------------------- ------------------ ------------------- ----------------------- -------------------
         LENDER               COMMITMENT       COMMITMENT ON AND       COMMITMENT %           COMMITMENT
                              PRIOR TO          AFTER EFFECTIVE         PRIOR TO             % ON AND AFTER
                            EFFECTIVE DATE          DATE             EFFECTIVE DATE         EFFECTIVE DATE
------------------------- ------------------ ------------------- ----------------------- -------------------
<S>                       <C>                <C>                 <C>                     <C>
BankBoston, N.A.          $30,000,000        $17,500,000         40%                     50%
------------------------- ------------------ ------------------- ----------------------- -------------------
Prudential Securities     $10,000,000        $0                  13.3333333%             0%
Credit Corporation
------------------------- ------------------ ------------------- ----------------------- -------------------
CIBC Inc.                 $35,000,000        $17,500,000         46.6666667%             50%
------------------------- ------------------ ------------------- ----------------------- -------------------
Total                     $75,000,000        $35,000,000.00      100%                    100%
------------------------- ------------------ ------------------- ----------------------- -------------------
</TABLE>

                                       9

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00004-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00004-of-00352.parquet"}]]