Johannesburg - South Africa's Competition Commission has referred construction firms WBHO, Group Five, Stefanutti and Basil Read to the Competition Tribunal for collusive tendering in building stadiums for the 2010 soccer World Cup, it said on Thursday.
"These firms colluded when bidding for tenders ... by, among others, allocating tenders among themselves and agreeing on profit margins to be achieved from these tenders," it said in a statement.
Murray and Roberts had been granted leniency in the case, it added.
READ: Firms 'divvied up World Cup tenders'
AFP reported that the commission said dozens of firms "colluded" over the megaprojects, in some instances allocating tenders among the themselves and reaching deals "agreeing on profit margins."
South Africa poured R20bn into the construction and refurbishment of 10 stadiums to be used for the showpiece soccer tournament.
Five of the venues were built from scratch, including the 94 500-seater Soccer City in Soweto, which hosted the opening match and the final.
Twenty-one companies have admitted wrongdoing and have paid settlements totalling R1.4bn.