Merrill Lynch Puttable FLOATs/RITES Trust puttable floating option tax-exempt receipts series PT-3173, relating to Trinity River Authority, Texas (Tarrant County Water Project) improvement and refunding revenue bonds series 2005, are rated 'AAA/A-1'. The long-term component of the rating is based on the MBIA-insured underlying bond. The short-term component of the rating is based on a liquidity facility from Merrill Lynch Capital Services ('N.R.') and a liquidity guarantee from Merrill Lynch&Co. Inc. ('A-1'). The expiration date of the liquidity facility is Sept.15, 2006. Merrill Lynch Puttable FLOATs/RITES Trust residual interest tax-exempt receipts series PT-3173, relating to Trinity River Authority, Texas (Tarrant County Water Project) improvement and refunding bonds series 2005, are rated 'AAA'. The long-term rating is based on
