Petrofac leads U.K. stock market lower By: MarketWatch July 14, 2011 at 03:53 AM EDT British stocks drop after Moody’s Investors Service warns of the rising risk of a U.S. default, with Petrofac leading the decline. Read More >> Related Stocks: HSBC Holdings Plc ADR Lloyds Banking Group Plc ADR Royal Dutch Shell Plc ADR