Exhibit 99.1350CERT

         Certification Pursuant to Section 906 of the Sarbanes Oxley Act

I, Terry K. Glenn, President of Merrill Lynch Large Cap Value Fund and Master
Large Cap Value Portfolio (together, the "Fund"), certify that:

      1.    The N-CSR of the Fund (the "Report") fully complies with the
            requirements of Section 13(a) or 15(d) of the Securities Exchange
            Act of 1934; and

      2.    The information contained in the Report fairly presents, in all
            material respects, the financial condition and results of operations
            of the Fund.

Dated: December 22, 2003

                                 /s/ Terry K. Glenn
                                 -----------------------------------------------
                                 Terry K. Glenn,
                                 President of Merrill Lynch Large Cap Value Fund
                                 and Master Large Cap Value Portfolio

A signed original of this written statement required by Section 906, or other
document authenticating, acknowledging, or otherwise adopting the signature that
appears in typed form within the electronic version of this written statement
required by Section 906, has been provided to Merrill Lynch Large Cap Value Fund
and Master Large Cap Value Portfolio and will be retained by Merrill Lynch Large
Cap Value Fund and Master Large Cap Value Portfolio and furnished to the
Securities and Exchange Commission or its staff upon request.


Exhibit 99.1350CERT

         Certification Pursuant to Section 906 of the Sarbanes Oxley Act

I, Donald C. Burke, Chief Financial Officer of Merrill Lynch Large Cap Value
Fund and Master Large Cap Value Portfolio (together, the "Fund"), certify that:

      1.    The N-CSR of the Fund (the "Report") fully complies with the
            requirements of Section 13(a) or 15(d) of the Securities Exchange
            Act of 1934; and

      2.    The information contained in the Report fairly presents, in all
            material respects, the financial condition and results of operations
            of the Fund.

Dated: December 22, 2003

                             /s/ Donald C. Burke
                             ---------------------------------------------------
                             Donald C. Burke,
                             Chief Financial Officer of Merrill Lynch Large
                             Cap Value Fund and Master Large Cap Value Portfolio

A signed original of this written statement required by Section 906, or other
document authenticating, acknowledging, or otherwise adopting the signature that
appears in typed form within the electronic version of this written statement
required by Section 906, has been provided to Merrill Lynch Large Cap Value Fund
and Master Large Cap Value Portfolio and will be retained by Merrill Lynch Large
Cap Value Fund and Master Large Cap Value Portfolio and furnished to the
Securities and Exchange Commission or its staff upon request.