LONDON (Standard&Poor's CreditWire) Dec. 22, 1999--Standard&Poor's today affirmed its double-'A' long-term and 'A-1'-plus short-term ratings on Marks&Spencer PLC and guaranteed related entities (see list below). The outlook remains negative. The affirmation follows Standard&Poor's review of the U.K. retail sector. The ratings reflect Marks&Spencer's strong position within its core U.K. retailing market and solid financial position. Like-for-like sales for the 26 weeks to Sept. 25, 1999, were down 7.8%, however, while profit before taxes amounted to £187 million ($304 million) before exceptional costs. This compares with profit of £316 million before exceptional items in the first half of last year. The group has also stated that results from its program of