NY -- Standard&Poor's CreditWire 9/29/97 -- Standard&Poor's today assigned its double-'A' rating to Tennessee Housing Development Agency's $88.01 million homeownership program bonds series 1997-3A (alternative minimum tax) and 1997-3B (non-AMT). The bonds are scheduled to sell Oct. 9. The outstanding double-'A' rating on the agency's bonds was affirmed, as was the outstanding double-'A'/'A-1'-plus rating on series 1996-5B, 1997-1, and 1997-2. The ratings on the bonds reflect: -- Credit quality of the single-family loan portfolio; -- Strength of indenture cash flows in the face of a potential transfer of funds to the state; -- Adequacy of reserves for liquidity; -- Sufficient loss coverage through excess assets; and -- Investments commensurate with the rating on the bonds. Series