More Americans will be traveling during this year's Christmas and New Year's holidays than ever, according to travel industry projections.

Greyhound, the nation's largest intercity bus line, said it will carry 1.34 million passengers between Dec. 18 and Jan. 3, or 10 percent more than for the period last year.In part, the increase is due to a recent boost in air fares and the limited amount of discount-priced seats on the nation's major airlines, said Fred G. Currey, Greyhound's chief executive officer, who was in Cleveland to meet with company employees.

"Airplane ticket prices are substantially higher this year, and they are a factor," Currey said Tuesday. "And bus fares are very moderately priced."

But Currey's contention was disputed by organizations representing the airlines and travel agents.

Most people traveling during the holidays bought their tickets "weeks and months ago before fares went up," said Philip G. Davidoff, president of Belair Travel of Bowie, Md., president-elect of the American Society of Travel Agents.

"What's going to happen next year, I don't know," Davidoff said. "If the increases are put into effect for January, it probably will mean more people will take buses than ever before."

Bill Horn, a spokesman for the Air Transport Association, which represents the nation's largest airlines, said a record 7 million Americans traveled by air during the Thanksgiving holiday weekend.

Between Dec. 17 and Jan. 2, U.S. airlines expect to transport at least 22 million people, or about 500,000 more than for the period last year, he said. That also would be a record, Horn said.

The nation's major airlines announced last month that they were raising most of their lowest discount fares and eliminating the cheap fares that can be booked a few days before a flight. But a week later, Eastern, Continental, Delta, and Northwest announced reductions in some fares.

"Those fare increases that were announced just prior to Thanksgiving affected a very small percentage of the travel market," Horn said.

Clifford Black, public relations manager for Amtrak, said the railroad carried a record number of passengers in the fiscal year that ended Sept. 30 and "it shows no signs of letting up."

But limited capacity makes it difficult for the railroad to set holiday records, he said.

"During the holiday seasons, they tend to sell out, making it impossible to improve from year to year and from one holiday season to the next," Black said.