Hundreds of Japanese travelers took advantage of a new no-visa rule on flights to the United States, and an airline spokesman said Friday that the first day went with hardly a hitch.

Starting Thursday, Japan and the United States began a 21-month pilot program that permits tourists and business visitors to enter without visas as long as they have a return or onward ticket and don't plan to stay for more than 90 days.The new system, warmly welcomed by the travel industry, is expected to boost travel to the United States by free-spending Japanese, as well as remove the visa routine for many Japanese.

The only hitch reported was a Japanese couple on a Japan Air Lines flight from Osaka to Honolulu who didn't have return tickets, said JAL spokesman Geoffrey Tudor.

"Their return tickets had been bought for them in Hawaii and were waiting in their hotel, but the immigration authorities wouldn't let them enter until they bought new return tickets," Tudor said. "Apart from that, we've heard of no other untoward incidents," he said.

At United Airlines, spokesman Bob Leu said about one-third of all Japanese passengers Thursday to the United States had gone without visas. That meant hundreds had tried the no-visa system, but Leu would not give exact numbers for reasons of commercial secrecy.

"It's a pretty high number, I think, for the first day," Leu said. "It went as smoothly as can be expected."

The United spokesman said it also had gone "quite easy" for U.S. citizens arriving in Japan without visas.

Japanese immigration authorities said it would take several months before they had statistical information on the number of Americans who came without visas, but there were no reports of problems.