Visa International, the world's leading credit company, has requested that its global financial member institutions ban international transactions through China UnionPay's system from August 1, the Beijing News reported.

No Visa card transactions outside the Chinese mainland - either payments or ATM withdrawals - should be conducted through the China UnionPay network, otherwise the bank will suffer a heavy charge, according to the request.

The first violation will result in a punishment of 50,000 U.S. dollars, and 25,000 U.S. dollars will be charged every month for further violations, according to the request letter sent to commercial banks.

Visa said on Tuesday that the action is a strict implementation of its global operation rules, as international transactions through other payment networks may bring Visa cardholders huge risks in the form of transaction disputes or data leakage.

The decision means cardholders in China will not be able to use Visa's global payment network through China UnionPay's system during overseas shopping in the future. The direct result is that they may have to pay 1- to 2-percent money exchange fees and face exchange rate risks before paying back the money.

The influence of Visa's decision will be large, according to the director of a commercial bank's credit card centre, as most of China UnionPay's overseas member institutions offer international services through Visa's global payment network, which covers more than 200 countries and regions.

Guo Tianyong, a banking expert from the Central University of Finance and Economics, said the action was triggered by interest disputes between Visa and China UnionPay.

Although Visa has a great number of cardholders in China, it still cannot set up a complete card issuing system, said Guo. On the other hand, its foreign cardholders can only use China UnionPay's payment network in China, which gives Visa a low profit margin.

Established in 2002, China UnionPay links all major banks and payment systems in China's major cities. The company has also expanded its overseas network to 90 countries and regions.

With China UnionPay holding back Visa's expansion in China and Visa doing the same in overseas markets, conflict is unavoidable, said Guo. He suggested card organizations in China moderately open the domestic market while expanding overseas, as competition is good for the development of the credit card industry in China.

China UnionPay hasn't yet responded to Visa's action.