South Africa's Economic Development Department will Tuesday request that the country's Competition Tribunal postpone the start of the hearing to decide on Wal-Mart Stores Inc.'s (WMT) proposed $2.4 billion offer for a controlling stake in African retailer Massmart Holdings Ltd. (MSM.JO), unions said Monday.

The tribunal is scheduled to hold the hearing from Tuesday to Friday, when the two retailers, unions and other interested parties will present evidence and testimony.

The United Food and Commercial Workers International Union said the government will submit an application first thing Tuesday asking for the hearing start date to be delayed so the government has time to put together its issues with the merger.

The UFCW said the tribunal will likely decide what to do before proceeding.

In January, Massmart said almost 98% of its shareholders voted in favor of the deal to sell a 51% stake to Wal-Mart at 148 rand a share and in February the South African Competition Commission recommended approval of Wal-Mart's proposed offer.

The Economic Development Department was late in sending its views to the commission.

Labor unions plan to present their case against the deal at the upcoming hearing. They are concerned that Wal-Mart's entry into South Africa will limit local food firms' ability to compete, leading to job losses and the demise of local industry.

The merger would be Wal-Mart's first step into Africa.

Massmart operates several wholesale and retail chains, including Game general-merchandise stores, Builders Warehouse for construction and Makro warehouse-club stores. The bulk of the company's 288 stores are in South Africa, although Massmart also operates in 13 other sub-Saharan countries.

-By Devon Maylie, Dow Jones Newswires; +44 (20) 7842 9483; devon.maylie@dowjones.com