Economy, Trade and Industry Minister Shoichi Nakagawa asked representatives of major credit card companies Thursday to protect customers and tighten information security in the wake of a massive card data theft in the United States, which caused more than 110 million yen in losses in Japan.

Nakagawa handed written requests to Tetsuro Maekawa, head of the Japan Consumer Credit Industry Association, Visa International Inc. General Manager for Japan Richard Chang and Douglas Lorentz, general manager of MasterCard International Inc.'s Japan branch.

"I regret that the incident has triggered anxiety among many cardholders in Japan. I hope the industry will investigate the cause in order to rebuild confidence in credit transactions as soon as possible," Nakagawa said.

Chang apologized over the case, while Maekawa and Lorentz pledged to alleviate customer concerns.

"We will work to regain our consumers' trust," Lorentz said.

Nakagawa also summoned executives of six major Japanese credit card firms, including JCB Co. and Nippon Shinpan Co., and asked them to deal with the case through measures that include swift provision of necessary information.

METI sent similar written requests to 24 other Japanese credit card companies.

In the document, Nakagawa asked the firms to protect customers through bolstered monitoring and the replacement of cards, and to reassure them that they are immune to payments incurred by unlawful use of stolen card data.

He sought responses to the requests from the industry as quickly as possible.

According to a METI survey, data on 21,000 MasterCard-linked cards issued by 26 Japanese firms and on 46,000 Visa-linked cards issued by 12 companies may have been leaked from U.S. data-processing company CardSystems Solutions Inc.

The ministry also said that 430 JCB cards and 15 cards issued in Japan in a tieup with Diners Club International Ltd. are among those whose data may have been stolen.