WASHINGTON — A government policy requiring that luggage arriving on flights from Canada be rechecked for bombs needs to be changed because it's causing up to 100,000 bags to be lost or delayed each year, according to several airport and airline leaders.

The policy, in effect since 2003, requires luggage from Canadian flights to be screened at U.S. airports before being put on connecting domestic planes.

That wastes time and money, airports and airlines say, because the luggage has already gone through bomb scanners in Canadian airports. Roughly 6 million bags from Canada are rescreened each year at U.S. airports, and 50,000 to 100,000 of them miss their connecting flights, according to a study by the Airports Council International and the Canadian Airports Council.

"It makes sense not to rescreen those bags," said Airports Council International security chief Charles Chambers.

The anti-rescreening effort gained momentum in January when it was recommended by the Secure Borders and Open Doors Advisory Committee in a report on ways to increase travel to the United States. Rescreening is "often redundant" because "the bags have already been screened," according to the committee, which is a group of 21 experts and business leaders appointed by Secretary of State Condoleezza Rice and Homeland Security Secretary Michael Chertoff.

The security law enacted after 9/11 requires all luggage on U.S. flights to be checked for bombs with machines that are not used in Canada, said TSA spokeswoman Ellen Howe.

Although Canadian technology is not approved under U.S. law, it is "at least as safe as the United States system," said Michael Skrobica, a vice president at the Air Transport Association of Canada, which represents Canadian airlines.