Exhibit 10.1

PERINI CORPORATION
FOURTH AMENDMENT AND WAIVER

        THIS FOURTH AMENDMENT AND WAIVER (this “Amendment”) is entered into as
of August 25, 2004 by and among PERINI CORPORATION, a Massachusetts corporation
(the “Borrower”), with its chief executive office at 73 Mt. Wayte
Avenue, Framingham, Massachusetts 01701, FLEET NATIONAL BANK, as Administrative
Agent (the “Administrative Agent”), and the Lenders under the Credit Agreement,
as defined below. Capitalized terms not otherwise defined herein shall have the
meanings ascribed to them in the Credit Agreement, as defined below.

R E C I T A L S

        WHEREAS, the Borrower, the Administrative Agent and the Lenders have
previously entered into a Credit Agreement dated as of January 23, 2002, as
amended by a First Amendment and Waiver dated as of February 14, 2003, by a
Second Amendment dated as of November 5, 2003 and by a Third Amendment dated as
of January 31, 2004 (the “Credit Agreement”);

        WHEREAS, the Borrower has requested that a waiver of the Event of
Default existing under Section 6.01(m)(iii) of the Credit Agreement resulting
from the sale of shares of the Borrower by certain of the shareholders
identified therein (the “Existing Default”) be granted and that certain
modifications be made to the Credit Agreement, and the Lenders have agreed to
grant such waiver and permit such modifications to the Credit Agreement on the
terms and conditions set forth herein;

        NOW THEREFORE, in consideration of the foregoing premises and the mutual
benefits to be derived by the Borrower, the Administrative Agent and the Lenders
from a continuing relationship under the Credit Agreement and for other good and
valuable consideration, the receipt and adequacy of which are hereby
acknowledged, the parties hereto agree as follows:

      A. Amendments to Credit Agreement.

1. Section 1.01 of the Credit Agreement is hereby amended as follows:

(a) The following defined terms are hereby amended in their entirety to read as
follows:

        “Applicable Margin” means the following percentage per annum (i) with
respect to any interest rate calculated with respect to the Adjustable Libor
Rate or the Prime Rate, and (ii) with respect to any fees payable on any Letter
of Credit, the margin set forth below:

--------------------------- ------------------------- -------------------------------------
        PRIME RATE                LIBOR LOANS                  LETTERS OF CREDIT
          LOANS
--------------------------- ------------------------- -------------------------------------
           .00%                      2.00%                           1.50%
--------------------------- ------------------------- -------------------------------------

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     (b) The defined term "Clean Down Period" is hereby deleted, and the
following defined term, "Clean Up Period", substituted in its place:

      "Clean Up Period" has the meaning set forth in Section 2.10(a).

     (c) The defined terms "Covered Charges" and "Interest Coverage Ratio" are
hereby deleted.

      (d) The following new defined terms are hereby added:

     "Consolidated EBITDA" means, for any period, the Borrower's and its
Consolidated Subsidiaries' Consolidated Net Income, plus (x) the sum of the
Borrower's and its Consolidated Subsidiaries' (i) tax expense, (ii) interest
expense, (iii) depreciation expense, and (iv) amortization expense, minus (y)
Consolidated Capital Expenditures, all for such period and as determined in
accordance with GAAP.

     "Consolidated Debt Service" means, at any date and for the period
specified, the sum of the Borrower's and its Consolidated Subsidiaries' (i) cash
interest expense, (ii) cash taxes, (iii) scheduled payments of principal and
interest, and (iv) Restricted Payments, including any paid or accrued during the
period of measurement on any of the Borrower's preferred stock.

      "Fixed Charge Coverage Ratio" means the ratio of Consolidated EBITDA to
Consolidated Debt Service.

     "Revolving Credit Termination Date" means the earlier of (i) June 30, 2007,
or (ii) the date of termination in whole of the Commitments pursuant to Section
6.01.

2. Section 2.10(a) of the Credit Agreement is hereby amended in its entirety to
read as follows:

     "(a) Semi-Annual Reduction in Revolving Loans. During each six (6) month
calendar period ending on June 30 and December 31 occurring prior to the
Revolving Credit Termination Date (each such period, a "Clean Up Period"), the
Borrower shall prepay all of the outstanding Revolving Loans for any ten (10)
consecutive Business Days. Any Revolving Loan repaid may be reborrowed after any
Clean Up Period in accordance with Section 2.01(a). "

3. Section 5.07 of the Credit Agreement is hereby amended in its entirety to
read as follows:

     "Section 5.07. Financial Covenants.

      (a) Minimum Net Operating Profit. As of the end of each fiscal quarter,
the Borrower shall not permit Net Operating Profit to be less than the amount

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set forth for such quarter below, calculated in the aggregate for the four
consecutive fiscal quarters then ending:

        ----------------------------------------- -------------------------------------------
               Fiscal Quarters Ending                  Minimum Net Operating Profit
        ----------------------------------------- -------------------------------------------

                9/30/04 and 12/31/04                           $25,000,000
        ----------------------------------------- -------------------------------------------

               3/31/05 and thereafter                          $27,500,000
        ----------------------------------------- -------------------------------------------

     (b) Minimum Fixed Charge Coverage Ratio. As of the end of each fiscal
quarter, the Borrower shall not permit the Fixed Charge Coverage Ratio to be
less than 1.50:1 for the four consecutive fiscal quarters then ending.

     (c) Minimum Consolidated Net Income. As of the end of each fiscal quarter,
the Borrower shall not permit Consolidated Net Income for such fiscal quarter to
be less than $1.00.

     (d) Minimum Consolidated Tangible Net Worth. As of the end of each fiscal
quarter, the Borrower will not permit Consolidated Tangible Net Worth to be less
than $62,090,000, plus on a cumulative basis and commencing with the Borrower's
fiscal quarter ending December 31, 2001, fifty percent (50%) of the Borrower's
Consolidated Net Income (without any reduction for losses) for each consecutive
two fiscal quarters of the Borrower ending on June 30 and December 31 of each
year.

     (e) Minimum Working Capital Ratio. As at the end of each of its fiscal
quarters, the Borrower shall not permit the ratio of (i) the consolidated
current assets (including cash and cash equivalents) of the Borrower and its
Consolidated Subsidiaries to (ii) the consolidated current liabilities
(excluding Debt under this Agreement) of the Borrower and its Consolidated
Subsidiaries to be less than 1.20:1."

4. Section 6.01(m) of the Credit Agreement is hereby amended in its entirety to
read as follows:

     "(m) any of the following: (i) any person or group of persons (within the
meaning of Section 13 or 14 of the Securities Exchange Act of 1934, as amended)
(other than the Exempt Group) shall have acquired beneficial ownership (within
the meaning of Rule 13d-3 promulgated by the Securities and Exchange Commission
under said Act) of 15% or more of the outstanding shares of common stock of the
Borrower; (ii) the Borrower shall cease to own 100% of the capital stock of any
Subsidiary Guarantor; or (iii) the Tutor-Saliba Corporation shall cease to be
deemed an Affiliate of the Borrower; or"

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5. Schedule A of the Credit Agreement is hereby deleted and replaced in its
entirety with Schedule A attached to this Amendment.

     B. Representations and Warranties. The Borrower represents and warrants to
the Administrative Agent and the Lenders that: (a) the Borrower has the full
power and authority to execute, deliver and perform its respective obligations
under, the Credit Agreement, as amended by this Amendment, (b) the execution and
delivery of this Amendment has been duly authorized by all necessary action of
the Board of Directors of the Borrower; (c) the representations and warranties
contained or referred to in Article IV of the Credit Agreement are true and
accurate in all material respects as of the date of this Amendment; and (d)
other than the Existing Default, no Event of Default has occurred and is
continuing or will result after giving effect to this Amendment and the
transactions contemplated by this Amendment and the Credit Agreement.

     C. Other.

     1.  This Amendment shall take effect upon receipt by the Administrative
Agent of:

     (i) this Amendment duly executed and delivered by the Borrower;

     (ii) an Assistant Clerk's Certificate executed by the Assistant Clerk of
the Borrower with regard to resolutions, organizational matters and officer
incumbencies;

     (iii) Legal Existence/Good Standing Certificate issued by the Massachusetts
Secretary of the Commonwealth for the Borrower;

     (iv) payment to the Administrative Agent, for the pro rata accounts of the
Lenders, of an extension fee of $100,000 to be debited to account number
#0236422481 with Fleet National Bank; and

     (v) Payment of all costs and expenses (including, without limitation, the
reasonable costs and expenses of the Administrative Agent's counsel) incurred by
the Administrative Agent in connection with this Amendment.

     2.   In reliance upon the representations of the Borrower to the
Administrative Agent and the Lenders that no Default or Event of Default exists
under the Credit Agreement, other than the Existing Default, the Lenders hereby
waive such Event of Default for any fiscal period in which such Event of Default
shall have occurred or be continuing. This waiver is limited to the Event of
Default described above and is not, nor shall it be construed as, a waiver of
any other Default or Event of Default under the Credit Agreement, now existing
or hereafter occurring, nor shall anything herein or the Lenders’ actions
hereunder be construed so as to imply that the Lenders have agreed, or are
obligated, to grant any future waivers under the Credit Agreement. Except as
otherwise expressly provided in this Amendment, all of the provisions of the
Credit Agreement shall remain in full force and effect.

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     3. This Amendment is executed as an instrument under seal and shall be
governed by and construed in accordance with the laws of The Commonwealth of
Massachusetts without regard to its conflicts of law rules. All parts of the
Credit Agreement, the Financing Documents and the Fee Letter not affected by
this Amendment are hereby ratified and affirmed in all respects, provided that
if any provision of the Credit Agreement shall conflict or be inconsistent with
this Amendment, the terms of this Amendment shall supersede and prevail. Upon
the execution of this Amendment, all references to the Credit Agreement in that
document, or in any related document, shall mean the Credit Agreement as amended
by this Amendment. Except as expressly provided in this Amendment, the execution
and delivery of this Amendment does not and will not amend, modify or supplement
any provision of, or constitute a consent to or a waiver of any noncompliance
with the provisions of the Credit Agreement, and, except as specifically
provided in this Amendment, the Credit Agreement shall remain in full force and
effect. This Amendment may be executed in one or more counterparts with the same
effect as if the signatures hereto and thereto were upon the same instrument.

[SIGNATURE PAGE FOLLOWS]

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     IN WITNESS WHEREOF, each of the Borrower, the Administrative Agent and the
Lenders in accordance with Section 9.05 of the Credit Agreement, has caused this
Amendment to be executed and delivered by their respective duly authorized
officers as of the date set forth in the preamble on page one of this Amendment.

                                       BORROWER:

WITNESSED:                             PERINI CORPORATION

/s/Donna E. Tannar                     By: /s/Susan C. Mellace
Donna E. Tannar                              Susan C. Mellace
    Print Name                               Treasurer

                                       ADMINISTRATIVE AGENT:

                                       FLEET NATIONAL BANK, as Administrative Agent

                                       By: /s/Thomas F. Brennan
                                              Thomas F. Brennan
                                              Senior Vice President

                                       LENDERS:

                                       FLEET NATIONAL BANK

                                       By: /s/Thomas F. Brennan
                                              Thomas F. Brennan
                                              Senior Vice President

                                       BANKNORTH, N.A.

                                       By: /s/Jon R. Sundstrom
                                              Jon R. Sundstrom
                                              Senior Vice President