Credit card giants Visa and MasterCard yesterday rejected US government accusations that the two companies had colluded to stifle competition in the US credit and charge card market.

On the first day of the anti-trust trial against the two companies in a federal court in New York, attorneys for Visa and MasterCard attacked their primary rival, American Express, accusing the company of having put pressure on the US government to bring the suit.

The two companies control some 75 per cent of the credit and charge card market between the two of them.