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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13D
                               (Amendment No. 3)*
                                       of
                           Tweedy, Browne Company L.P.


                                  SCHEDULE 13D
                               (Amendment No. 3)*
                                       of
                               TBK Partners, L.P.




                    Under the Securities Exchange Act of 1934

                             MATRIX SERVICE COMPANY
                                (Name of Issuer)


                     Common Stock, Par Value $0.01 per Share
                         (Title of Class of Securities)

                                    576853105
                                 (CUSIP Number)



                                 John D. Spears
                              52 Vanderbilt Avenue
                            New York, New York 10017
                                 (212) 916-0600
                 (Name, Address and Telephone Number of Persons
                Authorized to Receive Notices and Communications)



                                February 21, 1997
             (Date of Event which Required Filing of this Statement)



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If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(b)(3) or (4), check the following box [ ].

Check the following box if a fee is paid with the statement [ ]. (A fee is not
required only if the reporting person: (1) has a previous statement on file
reporting beneficial ownership of more than five percent of the class of
securities described in Item 1; and (2) has filed no amendment subsequent
thereto reporting beneficial ownership of five percent or less of such class.)
(See Rule 13d-7.)

* The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act,
but shall be subject to all the provisions of the Act (however, see the Notes).
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                                  SCHEDULE 13D

CUSIP No. 576853105                                         Page __ of __ Pages
- --------------------------------------------------------------------------------
1       NAME OF REPORTING PERSON
        S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

                Tweedy, Browne Company L.P. ("TBC")
- --------------------------------------------------------------------------------
2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*               (a) / /
                                                                        (b) /X/
- --------------------------------------------------------------------------------
3       SEC USE ONLY

- --------------------------------------------------------------------------------
4       SOURCE OF FUNDS*

                00
- --------------------------------------------------------------------------------
5       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
        TO ITEMS 2(d) or 2(e)                                               / /
- --------------------------------------------------------------------------------
6       CITIZENSHIP OR PLACE OF ORGANIZATION

                Delaware
- --------------------------------------------------------------------------------
                7       SOLE VOTING POWER
                                TBC has sole voting power with respect to
                        185,535 shares held in certain TBC accounts (as
                        hereinafter defined). Additionally, certain of the
                        general partners of TBC may be deemed to have sole power
                        to vote certain shares as more fully set forth herein.
  NUMBER OF     ----------------------------------------------------------------
   SHARES       8       SHARED VOTING POWER
BENEFICIALLY
  OWNED BY                      0 shares
    EACH        ----------------------------------------------------------------
 REPORTING      9       SOLE DISPOSITIVE POWER
   PERSON                       0 shares, except that certain of the general
    WITH                partners of TBC may be deemed to have sole power to
                        dispose of certain shares as more fully set forth
                        herein.
                ----------------------------------------------------------------
                10      SHARED DISPOSITIVE POWER
                                189,695 shares held in accounts of TBC (as 
                        hereinafter defined).
- --------------------------------------------------------------------------------
11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                189,695 shares
- --------------------------------------------------------------------------------
12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES*
                                                                            / /
- --------------------------------------------------------------------------------
13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                2.04%
- --------------------------------------------------------------------------------
14      TYPE OF REPORTING PERSON*

                BD, IA & PN
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!


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                                  SCHEDULE 13D

CUSIP No. 576853105                                         Page __ of __ Pages
- --------------------------------------------------------------------------------
1       NAME OF REPORTING PERSON
        S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

                TBK Partners, L.P. ("TBK")   
- --------------------------------------------------------------------------------
2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*               (a) / /
                                                                        (b) /X/
- --------------------------------------------------------------------------------
3       SEC USE ONLY

- --------------------------------------------------------------------------------
4       SOURCE OF FUNDS*

                WC and BK
- --------------------------------------------------------------------------------
5       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
        TO ITEMS 2(d) or 2(e)                                               / /
- --------------------------------------------------------------------------------
6       CITIZENSHIP OR PLACE OF ORGANIZATION

                Delaware
- --------------------------------------------------------------------------------
                7       SOLE VOTING POWER
                                0 shares, except that the general partners
                        in TBK, solely by reason of their positions, as such 
                        may be deemed to have shared power to vote these shares.
  NUMBER OF     ----------------------------------------------------------------
   SHARES       8       SHARED VOTING POWER
BENEFICIALLY
  OWNED BY                      0 shares
    EACH        ----------------------------------------------------------------
 REPORTING      9       SOLE DISPOSITIVE POWER
   PERSON                       0 shares, except that the general partners,
    WITH                solely by reason of their positions as such, may be
                        deemed to have shared power to vote these shares.
                ----------------------------------------------------------------
                10      SHARED DISPOSITIVE POWER
                                0 shares
- --------------------------------------------------------------------------------
11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                     0 shares
- --------------------------------------------------------------------------------
12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES*
                                                                            / /
- --------------------------------------------------------------------------------
13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                0  %
- --------------------------------------------------------------------------------
14      TYPE OF REPORTING PERSON*

                PN
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!


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PRELIMINARY NOTE

     This Amendment No. 3 is being filed because the filing persons are no
longer subject to the reporting requirements of Section 13(d) of the Securities
Exchange Act of 1934, as a result of the disposition of shares of Common Stock
of the Issuer as set forth more fully in Item 5 hereof. This Amendent No. 3 is
being filed by Tweedy, Browne Company L.P. ("TBC") and TBK Partners, L.P.
("TBK") who may be deemed to be members of a group. However, the filing of this
Amendment No. 3 should not be deemed an admission that TBC and TBK comprise a
group within the meaning of Section 13(d)(3) of the Securities and Exchange Act
of 1934, as amended (the "Act").

     This Amendment No. 3 relates to the Common Stock, $0.01 par value (the
"Common Stock"), of Matrix Service Company (the "Company"), which, to the best
knowledge of the persons filing this Amendment No. 3, is a company organized
under the laws of Delaware, with its principal executive offices at 10701 East
Ute Street, Tulsa, Oklahoma 74116.

     This Amendment No. 3 contains information regarding shares of Common Stock
that may be deemed to be beneficially owned by TBC. Such shares are held in the
accounts of various customers of TBC, with respect to which it has obtained sole
or shared voting power.

     Other than as set forth below, to the best knowledge of TBC and TBK, there
has been no material change in the information set forth in response to Items
1,2,4,6 and 7 of the Statement, as amended. Accordingly, those Items are omitted
from this Amendment No. 3.

ITEM 5.  INTEREST IN SECURITIES OF THE ISSUER

     (a)  As a result of the disposition of 420,000 shares of Common Stock in
open market transactions, TBC may be deemed to be the beneficial owner of an
aggregate of 189,695 shares of Common Stock, which constitutes approximately
2.04% of the 9,281,000 shares of Common Stock which TBC believes to be the total
number of shares of Common Stock outstanding. The TBC Shares are held in the TBC
Accounts.

     As a result of the disposition of 10,000 shares of Common Stock in open
market transactions, as of the date hereof, TBK does not beneficially own any
shares of Common Stock.

     Each of TBC and TBK disclaims that it is the beneficial owner of any of the
shares of Common Stock held in the TBC Accounts. The aggregate number of shares
of Common Stock with respect to which TBC and TBK could be deemed to be the
beneficial owner as of the date hereof, is 189,695 shares, which constitutes
approximately 2.04% of the 9,281,000 shares of Common Stock, which the filing
persons believe to be the total number of shares of Common Stock outstanding,
but nothing contained herein shall be construed as an admission that TBC is the
beneficial owner of any of the TBC Shares.

     The aggregate number of shares and percentage of Common Stock with respect
to which each of the General Partners may be deemd to be the beneficial owner by
reason of his being a general partner of TBC and TBK, respectively, is 189,695
shares, which constitutes approximately 2.04% of the 9,281,000 shares of Common
Stock outstanding. The aggregate number of shares and percentage of Common Stock
with respect to which Thomas P. Knapp may be deemed to be a beneficial owner by
reason of his being a general partner of TBK is 0 shares of Common Stock which
constitutes approximately 0% of the 9,281,000 shares of Common Stock
outstanding. However, nothing contained herein shall be construed as an
admission that any of the General Partners or Thomas P. Knapp is the beneficial
owner of any shares of Common Stock, except as set forth herein as expressly and
admittedly being beneficially owned by a particular General Partner or Thomas P.
Knapp.

     Each of TBC and TBK disclaims beneficial ownership of Common Stock held by
the other. Except as described herein, to the best knowledge of TBC and TBK, no
person who may be deemed to comprise a group with any of TBC, TBK, or any other
person named in Item 2 hereof, beneficially owns any shares of Common Stock.




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     (b)  TBC has investment discretion with respect to 189,695 shares of Common
Stock held by the TBC Accounts and has sole power to dispose or direct the
disposition of all of such shares. Of these shares of Common Stock, TBC has sole
power to vote or to direct the voting of 185,535 shares of Common Stock held in
certain TBC Accounts.

     Each of the General Partners of TBC, solely by reason of their positions as
such, may be deemed to have (i) shared power to dispose of or to direct the
disposition of all of the shares of Common Stock held in the TBC Accounts; and
(ii) shared power to vote or direct the vote of 185,535 shares of Common Stock
held in certain TBC Accounts.

     TBK has the sole power to vote or direct the voting of and dispose or
direct the disposition of the TBK Shares. Each of the General Partners and
Thomas P. Knapp, solely by reason of their positions as general partners, may be
deemed to have shared power to vote or direct the vote of and to dispose or
direct the disposition of the TBK Shares.



     (c)  During the sixty-day period ended as of the date hereof, TBC and TBK
have sold shares of the Common Stock in open market transactions, as follows:

REPORTING NO. OF PRICE PERSON DATE SHARES SOLD PER SHARE TBC Accounts 02/06/97 45,000 $7.1597 02/07/97 30,000 $7.2109 02/10/97 5,000 $7 1/4 02/11/97 30,000 $7.2083 02/12/97 50,000 $7.125 02/13/97 25,000 $7.125 02/18/97 45,000 $7.13889 02/19/97 70,000 $7.21875 02/20/97 60,000 $7.406250 02/21/97 60,000 $7.619790 TBK 02/07/97 10,000 $7.2109
Except as set forth in this paragraph (c) to the best knowledge of each of the filing persons, none of the persons named in response to paragraph (a) has effected any transactions in the shares of the Common Stock during the sixty day period ended as of the date hereof. (d) To the best knowledge of TBC, each of the persons maintaining an account with TBC has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of Common Stock held in said person's TBC Account. To the best knowledge of TBK, no person other than TBK has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the TBK Shares, except that the General Partners and Thomas P. Knapp may be deemed to have such rights and powers solely by reason of being general partners in TBK. (e) TBC and TBK ceased to be the beneficial owner of more than 5% of Common Stock on February 21, 1997. 7 SIGNATURE Each of Tweedy, Browne Company L.P. and TBK Partners, L.P., after reasonable inquiry and to the best of its knowledge and belief, hereby certifies that the information set forth in this Statement (which includes the Exhibit annexed hereto) is true, complete and correct. TWEEDY, BROWNE COMPANY L.P. By _________________________ Christopher H. Browne General Partner TBK PARTNERS, L.P. By _________________________ Christopher H. Browne General Partner Dated: February 25, 1997