Oil firms boost U.K. stocks to sixth day of gains By: MarketWatch January 30, 2013 at 05:29 AM EST U.K. stocks extend gains into a sixth straight session on Wednesday, with heavyweight banks and oil firms on the rise. Read More >> Related Stocks: BP Plc ADR Barclays Plc ADR HSBC Holdings Plc ADR Royal Bank Scotland Group Plc Royal Dutch Shell Cl B ADR