LONDON -- Standard&Poor's CreditWire 8/14/97 -- Standard&Poor's today has affirmed its ratings on Royal Bank of Scotland Group PLC (Royal Bank) and its principal subsidiary Royal Bank of Scotland PLC (see list below). The rating action follows yesterday's announcement of the agreed acquisition of the business of Birmingham Midshires Building Society. The acquisition, valued at between UK605 million and UK630 million, is subject to due diligence as well as to approval by Birmingham Midshires' members and by a number of regulatory bodies. Completion is expected in the second half of 1998. Royal Bank of Scotland has also issued 33 million ordinary shares (valued at about UK200 million) to life assurance company Scottish Widows -- substantially raising