Exhibit 12 (b) EX-99-906CERT Certification pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 James E. Ross, Principal Executive Officer and Gary L. French, Principal Financial Officer of the State Street Master Funds (the "Trust"), certify that: 1. This Form N-CSR filing for the Trust (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 Trust. By: /s/ James E. Ross --------------------------------- James E. Ross Principal Executive Officer of the Trust Date: March 6, 2009 By: /s/ Gary L. French --------------------------------- Gary L. French Principal Financial Officer of the Trust Date: March 6, 2009