Debit cards, already common in the United States and Europe, became available to holders of cash cards issued by more than 600 banks and financial institutions around the country. Retailers hope the extra convenience of debit cards will encourage consumers to spend more, while banks are set to gain from charges on transactions.

But analysts Site the relatively small number of retailers which will accept the cards, as well as some security concerns, as barriers to success.

"The way the average Japanese spends money will not change overnight," said Naomi Takagi, a retail analyst at HSBC Securities. She said the Japanese are so used to paying in cash that they will need time to get used to a new payment method.

The managing director of a company which sells traditional Japanese swords said that most major transactions are still made in cash. "Those Japanese customers who buy an expensive sword of more than one million yen ($9,300), for example, normally pay in cash rather than by credit card," said Kenichi Inami of Japan Sword Co Ltd in Tokyo. The new service, called "J-debit", is being expanded to more than 100,000 shops, department stores, hotels, petrol stations, restaurants and other businesses nationwide. That is 10 times the number of retailers who have accepted the cards since the service's low-key debut in January 1999.

But it is still far smaller than the number of shops that take credit cards, estimated at around three million. Takagi said the Japanese have gradually become accustomed to using credit cards, although plastic is still far less common than in the United States. "Under these circumstances, I rather doubt that the average Japanese will start using another new card overnight," Takagi said.

To make a purchase, a debit card is passed through a terminal, and the customer enters the same security code used for their bank's automatic teller machine.

Member shops pay a service fee to banks for each purchase, but this is less than that for purchases made by credit card, a fact welcomed by retailers that already accept credit cards.

Analysts say retailers which sell inexpensive day-to-day items, such as convenience stores and fast-food restaurants, stand to benefit the most from widespread use of the new cards, as most do not accept credit cards. But those shops are largely absent from the list of businesses that have agreed to take debit cards.