c54091_ex99-906cert.htm -- Converted by SEC Publisher, created by BCL Technologies Inc., for SEC Filing

EX-99.906CERT 3 c54091_ex99-906cert.htm c54091_ex99-906cert.htm -- Converted by SEC Publisher, created by BCL Technologies Inc., for SEC Filing

CERTIFICATIONS PURSUANT TO SECTION 906

EX-99.906CERT

CERTIFICATION

R. Jay Gerken, Chief Executive Officer, and Frances M. Guggino, Chief Financial Officer of Master Portfolio Trust - SMASh Series M Portfolio (the “Registrant”), each certify to the best of his knowledge that:

1. The Registrant’s periodic report on Form N-CSR for the period ended April 30, 2008 (the “Form N-CSR”) fully complies with the requirements of section 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Form N-CSR fairly presents, in all material respects, the financial condition and results of operations of the Registrant.


Chief Executive Officer		Chief Financial Officer
Master Portfolio Trust-		Master Portfolio Trust-
SMASh Series M Portfolio		SMASh Series M Portfolio



/s/ R. Jay Gerken		/s/ Frances M. Guggino
R. Jay Gerken		Frances M. Guggino
Date: June 27, 2008		Date: June 27, 2008

This certification is being furnished to the Securities and Exchange Commission solely pursuant to 18 U.S.C. § 1350 and is not being filed as part of the Form N-CSR with the Commission.