AMENDMENT NO. 1 TO
                       CORPORATE OPPORTUNITIES AGREEMENT

                This Amendment is made as of October 31, 1996 between Masco
Corporation, a Delaware corporation ("Masco"), and MascoTech, Inc., f/k/a Masco
Industries, Inc., a Delaware corporation ("Tech"), concerning that certain
Corporate Opportunities Agreement (the "Opportunities Agreement"), dated as of
May 1, 1987, between Masco and Tech.  All capitalized terms not otherwise
defined in this Amendment shall have the meaning given them in the Opportunities
Agreement.

                A.    Masco holds 24,824,690 shares of the Common Stock, par
value $1.00 per share, of Tech (the "Tech Common Stock");

                B.    Concurrently herewith, Tech has, among other things,
repurchased from Masco 17,000,000 shares of the Tech Common Stock;

                C.    In connection therewith, Masco and Tech desire to amend
certain provisions of the Opportunities Agreement as set forth herein.

                      IN CONSIDERATION of the mutual covenants and agreements
contained in this Amendment, the parties agree to amend the Opportunities
Agreement as follows:  

                1.    All references to "Industries" are hereby revised to be
references to "Tech."

                2.    Paragraph 1 is hereby amended to read in its entirety as
follows:

                      1.  Business Opportunities for Tech.  Neither Masco nor
                any of its subsidiaries shall consider undertaking any
                Third-Party Transaction (as hereinafter defined) which comes to
                the attention of Masco, Tech or any of their respective
                subsidiaries if such transaction involves metal-worked
                components, engineering or technical support services or
                aftermarket products in each case for the automotive industry
                and is not an Excluded Transaction (as hereinafter defined)
                unless Tech has first been provided with the opportunity to
                consider undertaking such transaction and thereafter either
                declines or fails, within a reasonable period, to conclude such
                transaction.  

                3.    Paragraph 2 is hereby amended to read in its entirety as
follows:  

                      2.  Business Opportunities for Masco.  Neither Tech nor
                any of its subsidiaries shall consider undertaking any
                Third-Party Transaction which comes to the attention of Tech,
                Masco or any of their respective subsidiaries if such
                transaction involves home improvement or building products or
                services unless Masco has first been provided with the
                opportunity to consider undertaking such transaction and
                thereafter either declines or fails, within a reasonable
                period, to conclude such transaction, except that a transaction
                by or with Emco Limited shall not be subject to the prohibition
                in this paragraph 2.  



                4.    Subparagraph 4(i) is hereby amended to read in its
entirety as follows:  

                      (i) A "Third-Party Transaction" shall mean any
                      acquisition, merger, consolidation or joint venture with,
                      investment (other than investments solely in marketable
                      securities or other noncontrolling minority investments)
                      in or any similar transaction involving a party other
                      than Tech, Masco, any of their respective subsidiaries or
                      any other entities in which on the date hereof any of
                      such corporations has investments not consisting solely
                      of marketable securities.

                5.    Subparagraph 4(ii) is hereby amended to read in its
entirety as follows:  

                      (ii)  An "Excluded Transaction" shall mean any
                      Third-Party Transaction with respect to a business which 
                      is not primarily involved in offering products or
                      services to the automotive industry, including the
                      automotive aftermarket. 

                6.    Paragraph 5 is hereby amended to read in its entirety as
follows:

                      5.  Duration.  The term of this Agreement shall expire on
                September 30, 1998; provided, however, that the term shall be
                extended automatically for a period of one year each October 1
                thereafter, subject to either party's right to terminate this
                Agreement by written notice to the other received at least 90
                days prior to any such October 1.  Termination of this
                Agreement shall not relieve either party of its obligations
                accruing hereunder through the effective date of such
                termination.

                7.    All other terms and conditions of the Opportunities
Agreement are hereby ratified and confirmed and remain in full force and effect.

                      IN WITNESS WHEREOF, the parties have duly executed and
delivered this Amendment as of the date first above written.

                                        MASCO CORPORATION

                                        By: /s/John R. Leekley
                                        Name:  John R. Leekley
                                        Title: Senior Vice President and
                                                 General Counsel

                                        MASCOTECH, INC.

                                        By: /s/ Timothy Wadhams 
                                        Name: Timothy Wadhams
                                        Title: Vice President-Controller and
                                                 Treasurer        
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