Johannesburg — MTN and Vodacom yesterday denied allegations of anti competitive behaviour despite confirmation by the Competition Commission that it was widening an antitrust probe to investigate possible collusion.

The commission uncovered information on possible anti competitive behaviour by the cellphone operators during an investigation into interconnection fees, commission head Shan Ramburuth, said yesterday.

"In the course of our investigation we have not restricted it to interconnect rates," he said.

Ramburuth declined to specify practices that were being added to the investigation. The commission had been investigating interconnect rates for the past three years, he said.

News of the investigation pulled down shares of both companies, Andrew Todd, an analyst with Imara SP Reid, said.

MTN stock fell as much as 1,3% to R120,90 in morning trading before closing at R122,50, while Vodacom shed as much as 2,2% to R54,49 and closed at R55,70.

Both companies have, however, denied that they were involved in collusive practices. "MTN denies that it has engaged in collusive conduct relating to interconnection," it said.

Vodacom was also equally not fazed by reports of a probe, with a spokesman also telling Busi ness Day that "Vodacom is not involved in anti competitive behaviour".

The commission has investigated three complaints against mobile operators, including MTN, relating to interconnection.

The government has focused on the rates cellphone firms charge for connecting calls across networks as a first step in lowering prices. With Bloomberg