MASTER AMENDMENT NO. 1 TO CREDIT SUPPORT AGREEMENTS

Exhibit 10.3

This Master Amendment No. 1 to Credit Support Agreements is dated as of September 18, 2008 (the " Amendment "), by and among LEGG MASON, INC. , a Maryland corporation (" Legg Mason "), LM CAPITAL COMPANY, LLC , a Maryland limited liability company (" LMC "), LM CAPITAL SUPPORT I, LLC , a Maryland limited liability company (" LMCSI "), LM CAPITAL SUPPORT II, LLC , a Maryland limited liability company (" LMCSII "), LM CAPITAL SUPPORT III, LLC , a Maryland limited liability company (" LMCSIII "), LM CAPITAL SUPPORT IV, LLC , a Maryland limited liability company (" LMCSIV " and, collectively with Legg Mason, LMC, LMCSI, LMCSII and LMCSIII, the " Support Providers " and each, individually, a " Support Provider ") and LIQUID RESERVES PORTFOLIO , a series of Master Portfolio Trust (the " Fund "), amending certain provisions of (a) the Capital Support Agreement dated as of March 31, 2008 by and among Legg Mason, LMC and the Fund (as amended and in effect from time to time, the " LMC CSA "); (b) the Capital Support Agreement dated as of March 31, 2008 by and among Legg Mason, LMCS I and the Fund (as amended and in effect from time to time, the " LMCSI CSA "); (c) the Capital Support Agreement dated as of March 31, 2008 by and among Legg Mason, LMCS II and the Fund (as amended and in effect from time to time, the " LMCSII CSA "); (d) the Capital Support Agreement dated as of March 31, 2008 by and among Legg Mason, LMCS III and the Fund (as amended and in effect from time to time, the " LMCSIII CSA "); and (e) the Capital Support Agreement dated as of March 31, 2008 by and among Legg Mason, LMCS IV and the Fund (as amended and in effect from time to time, the " LMCSIV CSA " and, collectively with the LMC CSA, the LMCSI CSA, the LMCSII CSA and the LMCSIII CSA, the " Capital Support Agreements " and each, individually, a " Capital Support Agreement ").

WHEREAS , each Support Provider and the Fund have agreed to modify certain terms and conditions of each Capital Support Agreement to which they are a party as specifically set forth in this Amendment;

NOW, THEREFORE , in consideration of the premises and the mutual agreements contained herein and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto hereby agree as follows:

§1.

Amendment to LMC CSA .  Legg Mason, LMC and the Fund hereby agree that the LMC CSA is hereby amended as follows:

(a)

the definition of "Maximum Contribution Amount" set forth in Section 1(f) of the LMC CSA is hereby amended by deleting such definition in its entirety and restating it as follows:

A/72635614.3

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"Maximum Contribution Amount" means $350,000,000.

(b)

Section 3(a) of the LMC CSA is hereby amended by deleting Section 3(a) in its entirety and restating it as follows:

(a)

If a Contribution Event occurs prior to the occurrence of a Termination Event, the Support Provider will make a Capital Contribution in an amount equal to the lower of (i) seventy percent (70%) of the Loss incurred as a result of such Contribution Event, or (ii) the Maximum Contribution Amount reduced by the amount of any Capital Contribution previously made by either Support Provider to the Fund under this Agreement.  The parties hereto acknowledge that the Related CSA of the Related LMCS Support Providers provides for a Capital Contribution to be made by the Related LMCS Support Providers under its Related CSA in an amount equal to the lower of (i) twenty percent (20%) of the Loss incurred as a result of such Contribution Event, or (ii) the Maximum Contribution Amount provided for in the Related CSA  of the Related LMCS Support Providers reduced by the amount of any Capital Contributions previously made by either Related LMCS Support Provider to the Fund under that Related CSA, and the Related CSA of the Related LMCS2 Support Providers provides for a Capital Contribution to be made by the Related LMCS2 Support Providers thereunder in an amount equal to the lower of (i) ten percent (10%) of the Loss incurred as a result of such Contribution Event, or (ii) the Maximum Contribution Amount provided for in the Related CSA of the Related LMCS2 Support Providers reduced by the amount of any Capital Contributions previously made by either Related LMCS2 Support Provider to the Fund under that Related CSA.

§2.

Amendment to LMCSI CSA .  Legg Mason, LMCSI and the Fund hereby agree that Section 3(a) of the LMCSI CSA is hereby amended by deleting Section 3(a) in its entirety and restating it as follows:

(a)

If a Contribution Event occurs prior to the occurrence of a Termination Event, the Support Provider will make a Capital Contribution in an amount equal to the lower of (i) twenty percent (20%) of the Loss incurred as a result of such Contribution Event, or (ii) the Maximum Contribution Amount reduced by the amount of any Capital Contribution previously made by either Support Provider to the Fund under this Agreement.  The parties hereto acknowledge that the Related CSA of the Related LMC Support Providers provides for a Capital Contribution to be made by the Related LMC Support Providers under its Related CSA in an amount equal to the lower of (i) seventy percent (70%) of the Loss incurred as a result of such Contribution Event, or (ii) the Maximum Contribution Amount provided for in the Rela