500.com files for $150 million U.S. Initial Public Offering

500.com Ltd., an online sports-lottery operator has filed for or a $150 million initial public offering in the U.S. The company didn’t say how many American depositary shares it will offer or at what price. 

Shenzhen-based 500.com offers betting services through the Web and mobile applications and has more than doubled its users to 18.4 million by the end of September, from 8.8 million at the end of 2010.