Exhibit 99.1350CERT

         Certification Pursuant to Rule 30a-2(b) under the 1940 Act and
                      Section 906 of the Sarbanes Oxley Act

Pursuant to 18 U.S.C. ss. 1350, the undersigned officer of Index Equity
Portfolio of BlackRock Funds and Master S&P 500 Index Series of Quantitative
Master Series LLC (the "registrants"), hereby certifies, to the best of his
knowledge, that the registrants' Report on Form N-CSR for the period ended June
30, 2008, (the "Report") fully complies with the requirements of Section 15d of
the Securities Exchange Act of 1934, as amended, and that the information
contained in the Report fairly presents, in all material respects, the financial
condition and results of operations of the registrants.

Date: August 22, 2008


/s/ Donald C. Burke
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Donald C. Burke
Chief Executive Officer (principal executive officer) of
Index Equity Portfolio of BlackRock Funds and
Master S&P 500 Index Series of Quantitative Master Series LLC

Pursuant to 18 U.S.C. ss. 1350, the undersigned officer of Index Equity
Portfolio of BlackRock Funds and Master S&P 500 Index Series of Quantitative
Master Series LLC (the "registrants"), hereby certifies, to the best of his
knowledge, that the registrants' Report on Form N-CSR for the period ended June
30, 2008, (the "Report") fully complies with the requirements of Section 15d of
the Securities Exchange Act of 1934, as amended, and that the information
contained in the Report fairly presents, in all material respects, the financial
condition and results of operations of the registrants.

Date: August 22, 2008


/s/ Neal J. Andrews
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Neal J. Andrews
Chief Financial Officer (principal financial officer) of
Index Equity Portfolio of BlackRock Funds and
Master S&P 500 Index Series of Quantitative Master Series LLC

This certification is being furnished pursuant to Rule 30a-2(b) under the
Investment Company Act of 1940, as amended, and 18 U.S.C. Section 1350 and is
not being filed as part of the Form N-CSR with the Securities and Exchange
Commission.