Baidu Inc. said Friday it will buy a 59 percent stake in Chinese group-buying site Nuomi for 160 million US dollars, as the search engine giant aims to expand its presence in mobile Internet.

Baidu said it had reached an agreement with Renren Inc., a leading social networking Internet platform in China and owner of Nuomi. The acquisition is expected to be finalized in the fourth quarter this year.

Nuomi was founded by Renren in 2010. Turnover of Nuomi in the second quarter of 2013 stood at about 120 million US dollars, 30 percent of which was derived from mobile devices.

Nuomi had 3.8 million active paying users during that period.

"Nuomi's group-buying platform and high-quality local information clearly complement Baidu's existing mobile location-based service (LBS) and maps offering," said Jennifer Li, chief financial officer of Baidu.

"Nuomi's broad geographical sales coverage and established consumer base will be instrumental in helping Baidu build out our LBS platform for local merchants," said Li.

"We believe the group-buying business has tremendous potential in China and will continue to benefit from the rapid growth of the mobile Internet, " said Joseph Chen, chairman and chief executive officer of Renren.

"Baidu's strategic investment will further enhance Nuomi's position in this sector and we are very excited about the synergies it creates," said Chen.

Baidu has stepped up with its investment in mobile Internet this year. Earlier this month, Baidu closed a 1.9 billion US dollar deal to acquire 91 Wireless Websoft, a major Chinese smartphone application distributor.

In May, Baidu spent 370 million US dollars to acquire the online video business of PPS in order to rival industry leader Youku Tudou.