UPDATE 1-UK Stocks-Factors to watch on Jan. 21

(Adds company news items and futures) Britain's FTSE 100 index is seen opening 15 points higher at 6,984, on Monday, according to financial bookmakers, with FTSE 100 futures down 0.11 percent ahead of the cash market open. * GLAXOSMITHKLINE: GlaxoSmithKline plc Chairman Philip Hampton will step down after more than three and a half years in the role, the drugmaker announced on Monday. * WILLIAM HILL: British bookmaker William Hill said on Monday its full-year adjusted operating profit was expec