UK Stocks-Factors to watch on Sept. 26

Britain's FTSE 100 index is seen opening down 6 points to 7,284 on Thursday, according to financial bookmakers. * SAINSBURY: The chief executive of Britain's Sainsbury's has reaffirmed his commitment to leading the supermarket group, saying a major investor event on Wednesday was not a beauty contest for his potential replacement. * PRUDENTIAL: Professional loan provider will spin off its UK and European insurance and asset management business M&G in October,