UK Stocks-Factors to watch on Aug 31

Aug 31 (Reuters) - Britain's FTSE 100 index is seen opening up 14 points on Thursday, according to financial bookmakers. * SHELL: Royal Dutch Shell staff have returned to a major oil and gas platform in the Gulf of Mexico in preparation to restart production one week after its shutdown due to Hurricane Harvey, industry sources said on Wednesday. * CO-OPERATIVE GROUP: Britain's Co-operative Group is in exclusive talks to buy Nisa, entering the fray days after larger rival Sainsbu