At a time when many transportation companies are pitching ever-faster delivery schedules, TNT Express Worldwide has introduced a new program geared to shippers willing to accept slower service in return for savings of up to 50 percent on shipments from the United States to Europe.

The program, called Say When, offers shippers three delivery options for documents and packages up to 70 pounds - the standard one to three days, four- five days and six-seven days.Tom Cox, TNT's chief executive for the Americas, said customer research revealed a strong interest in the slower service, especially among price- sensitive shippers with larger packages.

"Many companies with overseas offices and customers don't need to send all their documents and packages at the fastest transit time, especially for delivery of internal materials between offices," he said.

Greg Smith, vice president of Colography Group, a Marietta, Ga., consulting firm, said there's "tremendous interest" in such time-definite services. ''It doesn't have to be the quickest (service), but shippers have to know when it's going to be there. That's the key," he said.

Mr. Cox said shippers also are interested because of the ability to get a range of services from the same company. TNT plans to expand the service into Asia at some unspecified future time, he added.

The new program leaves some competitors unimpressed.

"That's not our bag," said Brandon Davis, a spokesman for Federal Express Corp. "We're an express transport company. Our customers seem to want a faster time-definite service, not slower."

Meanwhile, United Parcel Service said Monday that it now offers overnight service from more U.S. cities to more destinations combined in Europe, Asia, Canada and Latin America than any other major carrier.

John Alden, senior vice president for business development at UPS, said the carrier has improved its delivery time in more than 800 major trading lanes worldwide.