Visa, the world's largest electronic payment network has been sued by Australia's competition watch dog for alleged misuse of market power which is intended to boost its revenues in Australia.

The credit card company had allegedly prevented the retailers and customers from using a currency of their choice while making purchases or withdrawing money at the ATMs in Australia.

"The Australian Competition and Consumer Commission is concerned that Visa sought to stop the growth of competing dynamic currency conversion services and, as a result, limit the choices available to consumers," said Chairman Rod Sims in a statement.

''The alleged conduct by Visa gives rise to three concerns for the ACCC. First, it is alleged that travellers to Australia using a Visa payment card did not get to choose who does their currency conversion when withdrawing cash from an ATM. In particular, they are denied the ability to know the cost of transaction in their own currency at the time the transaction is made.

"Second, the ACCC alleges that Australian retailers were denied the opportunity to share in the revenue from processing at new merchant outlets.

"Finally, it is alleged that Australian suppliers of DCC services were, and continue to be, denied the opportunity to compete with Visa in relation to DCC services at ATMs".

Visa has been accused of preventing dynamic currency conversion services at Australian automatic tellers since October 2007. The company was also accused of engaging in exclusive deals by providing access to its payment network to Australian banks and retailers on the condition that they would only use Visa' currency conversion system.

The commission has taken action against VISA AP (Australia), VISA Inc, VISA USA Inc and VISA Worldwide Pty Ltd in the Federal Court in New South Wales, according to a report in Sidney Morning Herald.

The regulator is seeking penalties against Visa and declarations against all the companies that they 'took advantage of its substantial degrees of market power in the international payment card network".

"Visa has co-operated fully with the investigation by the ACCC and we strongly reject allegations that our rules on DCC services infringe Australia's competition laws,'' spokeswoman Zoe Hibbert said in a statement.