Wal-Mart said Monday that it will up its stake in Yihaodian to 51 percent as the giant U.S. retailer continues its move to grab a greater slice of the country's booming online market.

The deal is still waiting for Chinese regulatory approval, according to a statement released Monday by Wal-Mart.

Wal-Mart said in May last year that it had signed a deal to buy a minority stake in Yihaodian but it did not reveal the size of the stake.

Founded in Shanghai in July 2008, Yihaodian sells a range of goods including food, cosmetics and consumer electronics.

The e-commerce company says it has logistics centers in five major Chinese cities, namely Beijing, Shanghai, Guangzhou, Wuhan and Chengdu, and delivers to 34 cities across the country.

At the time of the May 2011 deal, the website had nearly 1 million registered users, and its sales exceeded 800 million yuan (127 million U.S. dollars) in 2010.

Wal-Mart Stores, the world's biggest retailer, has more than 370 retail outlets in 140 Chinese cities.