Senate Majority Leader George Mitchell, D-Maine, said Friday he'd like to see the Brady bill changed to require background checks of handgun purchasers during a seven-day waiting period, instead of leaving the checks optional.

Gun-control backers said they were pleased by Mitchell's remarks since he had been widely regarded as an opponent of the House-passed bill.Mitchell said the bill is ineffective because it doesn't require local police to conduct checks of criminal records during the seven-day waiting period it requires.

"I don't think that the Brady bill as currently written will accomplish that which its supporters say they want to accomplish," Mitchell told a group of reporters.

"I have never opposed the concept of a waiting period. I've made that clear," said Mitchell.

Mitchell said that requiring background checks of gun purchasers to keep felons or people with histories of mental illness from obtaining handguns would make the bill more effective.

The majority leader said he would also favor giving states financial incentives to computerize and centralize their criminal rec-ords so that a system of "instant checks" in gun stores could be done some day.

The National Rifle Association, which opposes the Brady bill, supported an unsuccessful amendment in the House that would have required the Justice Department to set up a nationwide hot line for such records checks in six months.

The "point-of-sale" records checks, supposed to have been completed in 24 hours, would have replaced the Brady bill's seven-day waiting period.

But the House defeated the substitute proposal, sponsored by Rep. Harley O. Staggers Jr., D-W.Va., and passed the Brady bill Wednesday, 239-186.