Renren Inc (NYSE:RENN) shares jumped after it sold its majority stake in the group-buy site Nuomi.com to Chinese IT powerhouse Baidu.com, Inc. (ADR) (NASDAQ:BIDU), reports Belinda Cao for Bloomberg. Baidu’s shares fell 0.7 percent after the deal was announced, its biggest decrease all week. Baidu expanding into other areas Baidu.com, Inc. (ADR) (NASDAQ:BIDU) is the dominant Chinese search engine (think Google) and like many IT companies trying to handle the transition to mobile computing, it has been looking to expand into other areas. The $160 million purchase gives it a majority share (59 percent) of the group buying site Nuomi.com, which…