US online auction giant eBay will take a controlling stake in South Korea's biggest online marketplace Gmarket in a deal worth up to €916 million dollars, according to the two companies.

Gmarket's directors voted unanimously to approve the transaction expected to be completed by the end of June, with eBay offering €18 dollars a share.

The total purchase price would be about €916 billion if all outstanding shares are tendered. Under an agreement with Gmarket's management and investors, eBay will hold at least 67 per cent of the South Korean firm, a statement said.

Shareholders that have signed agreements to tender include Interpark Corporation and its chairman Lee Ki-Hyung, current holders of about 34 per cent of Gmarket.

eBay will combine Gmarket's operations with its own Korean subsidiary, Internet Auction Company, while maintaining separate sites.

By acquiring Gmarket the California-based company will become the largest player in South Korea's online auction market with a 37 per cent share.

"The combination of Gmarket and Internet Auction Company establishes an exceptionally strong leadership position for eBay in one of the world's largest, most dynamic and innovative e-commerce markets," John Donahoe, eBay's president and chief executive officer, said in a statement.

"This deal creates strong operational synergies between the two market leaders, offers more opportunities for sellers and enhances our ability to serve complementary consumer segments."

Ku Young-Bae, Gmarket's president and chief executive officer, said the transaction will help his firm expand beyond South Korea.

"eBay also expects the combination with Gmarket to provide a potential platform for further expansion within Asia," the companies said in their statement.

South Korea's Fair Trade Commission last September gave conditional approval for the deal when it authorised eBay's purchase of the 34 per cent stake from Interpark and its chairman Lee.