LONDON (Standard&Poor's CreditWire) June 22, 1999--Standard&Poor's today affirmed its ratings on Royal Bank of Scotland PLC (Royal Bank) and Royal Bank of Scotland Group PLC. The outlooks are stable. (See list below.) The rating action follows yesterday's announcement that Royal Bank's wholly owned subsidiary Citizens Financial Group Inc. has agreed to acquire UST Corp. of Boston, Massachusetts for UK875 million. The acquisition's consideration is in cash, and the deal is expected to be completed by early 2000. It is subject to approval by UST shareholders and by Federal and State regulators. Strategically, this move is in line with Citizens' successful policy of acquiring northeastern U.S. banks and generating economies of scale through consolidation and rationalization. Citizen's