As the rally ran out of steam, European shares slipped late in the trading session on Friday and ended over 0.5 percent lower.Some said that was down to profit taking. Others blamed doubts over the economic recovery. Whatever the cause, crude oil prices retreated sharply, falling 1.5 percent. Major energy companies retreated, reversing their earlier gains. Drugmakers were among the worst performers. Ireland’s Elan lost nearly a quarter of its value after European regulators said they will review its multiple sclerosis drug Tysabri following reports of 23 cases of a potentially deadly brain infection. London’s FTSE 100 finished up 0.7 percent as lower GDP in Britain suggested interest rates there will remain low and the British government may extend its quantitative easing efforts to support the UK economy.