Merrill Lynch Puttable FLOATs/RITES Trust puttable floating option tax-exempt receipts series PT-2419 (Southern Illinois University), relating to Southern Illinois University Board of Trustees housing and auxiliary facilities system revenue bonds series 2004A, are rated 'AAA/A-1+'. The long-term component of the rating is based on the Ambac-insured underlying bond. The short-term component of the rating is based on a liquidity facility provided by WestLB AG, which is scheduled to expire on Nov. 15, 2005. Merrill Lynch Puttable FLOATs/RITES Trust residual interest tax-exempt securities receipts series PT-2419 (Southern Illinois University), relating to Southern Illinois University Board of Trustees housing and auxiliary facilities system revenue bonds series 2004A, are rated 'AAA'. The long-term component of the rating is based on the Ambac-insured underlying