European shares turned negative in choppy trading on Thursday, tracking falls on the U.S. equity markets, while a decline in French drugmaker Sanofi also weighed on the region's bourses, Reuters reported. The pan-European FTSEurofirst 300 index was down by 0.1 percent at 1,150.71 points by 1530 GMT, having at one stage been up as much as 0.5 percent to 1,158.26 points. U.S. equities also extended losses, with American housebuilding stocks falling sharply. A 3.7 percent fall at Sanofi took the most points off the FTSEurofirst 300 index, after Sanofi said its earnings could fall this year. -- SPA