South African competition authorities have given the go-ahead to US store giant Wal-Mart's $2.4bn (£1.5bn) bid for local retailer Massmart.It has imposed conditions on the bid, such as a ban on firing workers in the first two years.It has also said that Wal-Mart must have a programme for developing local suppliers.Wal-Mart's bid for 51% of Massmart is seen as a test case for major foreign investment in South Africa.The world's biggest retailer had threatened to withdraw from the deal if targets were placed on buying from local suppliers.Unions and three government departments opposed the deal, fearing that Wal-Mart's global supply chain could squeeze domestic companies.Unions threatened to boycott the retailer if the deal was allowed to go ahead.In addition to the firing freeze, Wal-Mart must also give preference to re-employing 500 staff who were laid off in 2010.Source: BBC