eBay announced an agreement Wednesday to acquire Gmarket for a price of up to $1.2 billion, and Yahoo has agreed to sell its 10 percent stake in the South Korean e-commerce site in a move that would raise about $120 million.

Gmarket's board unanimously approved eBay's tender offer, in which the online auction and commerce site will pay a cash price of 31,767 Korean won, or $24, per share for all common shares and all American Depository Shares. eBay said it's assured of owning at least 67 ...