"The next step in the approval process is the Competition Tribunal hearing, followed by its ruling on the transaction," the firms said.

"We are delighted that the Commission has recognised the inherent benefits in this proposed transaction for South African consumers, suppliers, associates/employees and all other stakeholders," said Walmart International CEO Doug McMillon.

Competition authorities are the last hurdle for the world's biggest retailer to take a controlling stake in the South African firm after shareholders overwhelmingly voted in favour of the deal in January.

Massmart CEO Grant Pattison said it was difficult to predict an exact timing for the tribunal hearing.

Last month COSATU, South Africa's largest labour federation, threatened the "mother of all boycotts" in opposition to the deal.

The South African Commercial, Catering and Allied Workers Union (SACCAWU), a COSATU affiliate, has formed an "Anti-Walmart Coalition" against the deal. The coalition wants to keep existing labour and supplier agreements, among other things.

In Saturday's statement, Pattison said Massmart was engaged in ongoing discussions with SACCAWU as part of its effort to respond to the union's concerns related to the transaction.