NY -- Standard&Poor's CreditWire 8/22/96 -- Standard&Poor's today has affirmed its ratings on HSBC Americas Inc. and its bank subsidiary, Marine Midland Bank (see list below), following the bank's agreement to acquire First Federal Savings&Loan Association of Rochester. The acquisition enhances Marine Midland's upstate franchise, and reflects HSBC's commitment to its strategy to expand its U.S. presence. On Aug. 8, 1996, Standard&Poor's raised its ratings on both entities to their current levels to reflect the improved financial performance of HSBC Americas and Marine Midland, as well as the support of the parent company, HSBC Holdings PLC. OUTLOOK: Stable. Although Marine is expected to maintain a solid financial performance, the company will continue