Visa, Sprint Plan New Calling Card Service : Communications: It would offer 25% off on long-distance calls. AT&T;’s Universal Card carries a 10% discount.

Visa U.S.A. and Sprint announced an alliance Wednesday for a new calling card service, the latest effort by the credit card industry to expand the range and power of plastic money.

The move comes as card issuers fine-tune the services offered with their cards to tailor them more closely to consumer needs.

For example, Citibank said Tuesday that it was offering a new program that extends the manufacturer’s warranty on toasters, compact disc players and other appliances purchased with a Citibank Visa or MasterCard for the expected life of the product.

Improving service and developing closer customer relationships are key trends in the competitive industry, which increasingly is tailoring cards for specific audiences.

Next month, for example, television commentator Louis Rukeyser plans to introduce a credit card. The “Louis Rukeyser Wall Street Club Card,” to be unveiled by Union Planters National Bank of Memphis, Tenn., will offer a six-month introductory 5.9% annual rate, then go to a floating 8.9%, a bank spokeswoman said.

The MasterCard-branded card will be offered to the 450,000 members of Rukeyser’s investment club.

The notion of building closer relationships with existing customers was a key motivation behind the Visa and Sprint alliance. Visa cardholders could save up to 25% on domestic long-distance calls by using the service.

U.S. Visa cardholders would dial “10 VSA” to gain access to the service, then use their home phone number and a personal four-digit Visa number for authorization. Users have the option of paying Visa or Sprint.

“It’s another part of the payment systems market that the card is now very useful for,” said Richard Hagadorn, senior vice president for Visa U.S.A.

He said the alliance will help Visa tap an $8-billion market in the United States.

Visa cardholders will be able to make calls from their homes or virtually anywhere they travel, officials said. The new service will be launched in selected areas of the United States by late fall of this year at no extra cost.

Visa has also struck an alliance with British Telecom, Hong Kong Telecom and Telestra, the Australian communications company, for long-distance calling services.

The new Visa-Sprint alliance will compete with the AT&T; Universal Card, a credit card introduced three years ago that offers a 10% discount on AT&T; long-distance calls. But AT&T; said calling card users save more than 25% off normal rates by using special calling plans.

Several other regional long-distance companies, the former “Baby Bells,” have also introduced co-branded credit cards in recent months.