<PAGE>

                               FIRST AMENDMENT TO
                   LETTER OF CREDIT AND REIMBURSEMENT AGREEMENT


     THIS FIRST AMENDMENT TO LETTER OF CREDIT AND REIMBURSEMENT AGREEMENT (this
"Amendment") is made as of September 12, 1995, by and between Koll Real Estate
Group, Inc., a Delaware corporation ("KREG") and Nomura Asset Capital Corpora-
tion, a Delaware corporation (together with its successors and assigns, "NACC").

     WHEREAS, KREG and NACC have entered into that certain Letter of Credit and
Reimbursement Agreement, dated as of December 20, 1994 (the "Loan Agreement").

     WHEREAS, KREG and NACC now desire to amend the Loan Agreement, upon the
terms and conditions set forth herein.

     NOW THEREFORE, in consideration of the foregoing, the terms and conditions
contained herein, and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, KREG and NACC agree to amend the
Loan Agreement as follows:

1.   Section 1.1 of the Loan Agreement is hereby amended by inserting the
following definitions in lieu of the definitions set forth for such terms in the
Loan Agreement:

          "EAGLE CREST SECURITIES ACCOUNT" shall mean that certain securities
account # 324-141517, established with Wells Fargo Bank, N.A. in the name of
NACC, as secured party, which, together with the KREG Securities Account is the
subject of the Securities Account Agreement, as amended.

          "INFRASTRUCTURE" shall mean infrastructure improvements to real
property, including, without limitation, road, walkways, sewers, storm drains,
water mains, community walls and landscaping and all improvements for the Eagle
Crest Project set forth on the "Construction Plans" (as such term is defined in
the Construction Loan Agreement).

          "NACC SHARE" shall mean, (i) from and after the date hereof, eighty
percent (80%) of all Net Cash Proceeds from each and every Permitted


<PAGE>
Sale; and (ii) from and after six months from the date hereof, ninety percent
(90%) of all Net Cash Proceeds from each and every Permitted Sale.

2.   Section 7.4 of the Loan Agreement is hereby amended by:

     (a)  deleting the phrase in the fifth line of such section which reads:
"eighty percent (80%) of all Net Cash Proceeds from such permitted sale (the
"NACC SHARE")" and inserting in its place the phrase "the NACC Share"; and

     (b)  adding the following at the end of such Section:

          "In the event that SBC elects to sell all or any portion of the Bolsa
Chica Project to the American Land Conservancy, or any other purchaser thereof,
then NACC shall permit such sale provided that Net Cash Proceeds therefrom are
(i) sufficient to repay any and all amounts then outstanding under the Loan
Documents and the Construction Loan Documents and (ii) actually applied to the
repayment of such amounts."

3.   Section 10.3 of the Loan Agreement is hereby amended by deleting subsection
10.3 (f).

4.   Section 12.2 of the Loan Agreement is hereby amended by adding the
following language after the word "liabilities" in the fourth line of such
Section:

          "(other than up to $30,000,000  for actual Bolsa Chica development
          costs incurred since January 1, 1995 (which costs may be included in
          the calculation of Signal's assets and liabilities for purposes of
          calculating the Minimum Net Worth Amount))"

5.   Section 12.6 of the Loan Agreement is hereby deleted in its entirety and
replaced with the following:

     12.6 USE OF REMAINING NET CASH PROCEEDS; COMPLETION OF EAGLE CREST PROJECT
INFRASTRUCTURE.

          (a)   KREG shall cause Signal to allocate and apply any and all Net
Cash Proceeds resulting from any Permitted Sale remaining after the proper
payment and application of the NACC Share in accordance with the terms hereof,
to the payment of "Construction Costs" (as such term is defined in the
Construc-


                                        2

<PAGE>

tion Loan Agreement) in connection with the construction of the Eagle Crest
Project Infrastructure.

          (b)  KREG covenants and agrees that it shall complete construction (or
cause the completion of construction) of the Eagle Crest Project Infrastructure
on or before the Maturity Date of the Construction Loan.

6.   Section 13.1(c) of the Loan Agreement is hereby modified by deleting clause
(v) thereof and replacing it with the following:

"(v) any other assets (other than the Collateral or the Bolsa Chica Project)
having an aggregate value of $5,000,000 or less per year; provided, however,
that the proceeds of any such sales are either applied to the repayment of the
Construction Loan and/or the Repayment Amount or are otherwise used by Signal
for the development of the Collateral Property or the Bolsa Chica Project."

7.   Section 13.3(h) of the Loan Agreement is hereby deleted in its entirety and
replaced with the following Sections 13.3(h):

     "(h)(i) Indebtedness incurred by a Subsidiary of KREG in connection with
the acquisition of a company involved in the development, entitlement or con-
struction of residential housing or commercial projects or in connection with a
Quick Flip Transaction, or an Asset Purchase Transaction permitted hereunder;
provided that such Indebtedness is expressly non-recourse to KREG, Signal and
the Guarantors and is not secured by any of the Collateral or the Bolsa Chica
Project and provided further that NACC shall have consented to the incurrence of
such Indebtedness, which consent shall not be unreasonably withheld, conditioned
or delayed; and (ii) Indebtedness in connection with build-to-suit transactions
incurred by KREG Operating Company or its Subsidiaries, including guarantees of
completion made in connection with such build-to-suit transactions; provided
that the Indebtedness resulting from such build-to-suit transactions does not in
the aggregate exceed $20,000,000."

8.   In addition to those expenses set forth in Section 17.5 of the Loan Agree-
ment, KREG agrees to pay or reimburse NACC for paying: (a) all reasonable out-
of-pocket expenses of NACC and any servicer of the Loan (including, without
limitation, the reasonable fees, charges and disbursements of Skadden, Arps,
Slate, Meagher & Flom, counsel to NACC, in connection with the negotiation,
preparation, execution and delivery of this Amendment) and NACC's due diligence
in connection with the Collateral Properties; (b) all reasonable out-of-


                                        3



<PAGE>

pocket travel and third party due diligence expenses of NACC and any servicer
(including the reasonable fees, charges and disbursements of counsel to NACC
and such servicer ) in connection with the preparation, negotiation, review
and execution of any documents required pursuant hereto or to the Loan
Documents; and (c) all reasonable costs and expenses of NACC and such
servicer (including reasonable counsel fees, charges and disbursements) in
connection with any Default and any enforcement or collection proceedings
resulting therefrom, including, without limitation, in connection with any
bankruptcy, insolvency, liquidation, reorganization, moratorium or other
similar proceedings involving KREG, Signal or the Guarantors or a "workout"
of the Loan.

9.   This Amendment may be executed in any number of counterparts, all of which
taken together shall constitute but one and the same instrument and any of the
parties hereto may execute this Amendment by signing any such counterpart.

10.  Except as expressly amended hereby, the Loan Agreement shall continue
unmodified and remain in full force and effect.


                                        4

<PAGE>

          IN WITNESS WHEREOF, the parties hereto have caused this Amendment to
be executed as of the date and year first above written.

                            KOLL REAL ESTATE GROUP, INC.,
                            a Delaware corporation


                            By:  /s/ RAYMOND J. PACINI
                                 _____________________________
                                 Raymond J. Pacini
                                 Chief Financial Officer and
                                 Executive Vice President



                            NOMURA ASSET CAPITAL CORPORATION
                            a Delaware corporation


                           By:  /s/ RICHARD A. MAGNUSON
                                _____________________________
                                Richard A. Magnuson
                                Vice President





                                        5