JOHANNESBURG — A South African chain’s shareholders have overwhelmingly accepted Wal-Mart’s offer to buy 51 percent of their company, the chief executive said Monday, paving the way for the giant U.S.-based retailer to enter Africa.

Massmart said 97 percent of shareholders who voted Monday approved the proposal – 75 percent had been needed. Wal-Mart offered about $20 per share in a deal worth about $2 billion. The deal will have to be approved by South Africa’s anti-monopoly regulators.

Wal-Mart, based in Bentonville, Ark., has 8,692 stores in 15 countries, among them Brazil, China and India. But it has not until now ventured into Africa.