BEIJING—Baidu Inc., China's largest search engine by revenue, released its own mobile-Internet browser and said Monday it would invest in a new cloud-computing center in a bid to gain more control over how Internet users in China access the Web through smartphones.

The launch of the browser—which offers speedy download times, Baidu services, and can run applications directly off the Internet—is the most recent step by Baidu to gain a better hold of a young but rapidly expanding mobile-Internet market.

The...