Skadden, Arps, Slate, Meagher & Flom and Shearman & Sterling have the lead roles on Chinese micrcoblogging site Sina Weibo’s planned $500 million U.S. initial public offering.

Weibo was launched by Sina Corp. in 2009 as a Chinese version of Twitter. In 2010, competitors including Tencent Holdings Ltd, NetEase Inc. and Sohu.com Inc. also launched similar products, but Sina Weibo so far remains China’s largest and most influential microblogging service. The company reported 61.4 million daily active users at the end of December, accounting for over half of all microblog users in China.