The head of the Maryland State Police has instructed his officers to delay approval of handgun sales to people who have criminal charges pending against them, according to a report he delivered yesterday to state lawmakers.

The change has nearly doubled the number of gun sales put on hold by state police, the report said.

Under state law, a hold allows authorities additional time past the mandated seven days for a background check if questions arise upon initial review of a gun purchase application.

In an interview yesterday, Maryland State Police Superintendent David B. Mitchell said that the number of holds in the first five months of 1999 was 2,094, compared with 2,601 for all of 1998.

Gun sales to people with pending criminal charges are automatically delayed until the charges are resolved.

Mitchell's report to the legislature also stated that his agency has corrected lapses in the way it conducts criminal background checks of handgun buyers and now reviews all applications within 48 hours.

State legislators had threatened to withhold $1 million from next year's state police budget unless the agency could prove by June 1 that it had fixed a series of mistakes that enabled 49 convicted criminals and other ineligible buyers to purchase handguns last winter because police took too long to process their applications.

The errors stemmed from a backlog of about 1,500 overdue background checks that surfaced last December and continued until mid-March, when the problem was publicized. In response, Mitchell replaced three of his top commanders and ordered an internal investigation into how the backlog was allowed to develop.

Under federal and state law, people who have been convicted of a felony, certain misdemeanors or a crime involving domestic violence are forbidden to purchase firearms. Those with a history of alcoholism, drug addiction or mental illness are also prohibited.

Under Maryland law, gun dealers must wait seven days before completing a handgun sale so that state police have time to carry out a criminal background check. If police do not respond or notify dealers of problems after a week, dealers may go ahead and release the weapon to the buyer.

Mitchell said he changed the policy concerning gun purchasers with pending criminal charges in response to a case in Laurel in March in which a woman who had been charged with -- but not convicted of -- theft was allowed to buy a handgun and later used the weapon in a domestic shooting.

"It doesn't mean the applicant is being denied," Mitchell said of the holds. "It just means we're being more thorough."

Mitchell said three factors -- computer foul-ups, poorly trained employees and bad management -- played roles in the backlogs that led to the improper sales.

He said a software glitch with a new computer system began causing the delays in November. The problem was compounded by employees for whom "the use of personal computers was foreign," according to the report. Making matters worse, state police brass failed to authorize employees in the agency's licensing division to work overtime to correct the situation, Mitchell said.

"What didn't happen was we didn't compensate for the backlog that was growing and bursting at the seams . . . for reasons that are just totally inexplicable to me," Mitchell said.

Mitchell said the backlog was eliminated 11 days after he learned of it in March.

Some dealers had complained that state police would often take weeks or months to complete background checks. But Mitchell said yesterday that his agency now conducts all background checks within 48 hours of receiving an application. State police received about 28,000 applications last year.

Some legislators who previously had criticized the state police for the background check problems said yesterday that they were pleased with Mitchell's report.

"I was extremely concerned with what had happened," said state Sen. Ida G. Ruben (D-Montgomery), who sponsored the measure to withhold $1 million from the state police budget if the agency did not provide assurances that it had cleaned up the problem. "But the most important aspect was that Col. Mitchell moved swiftly and that the people who let all this slip were moved to another job. . . . I don't think we'll have this problem again."

Del. Cheryl C. Kagan (D-Montgomery) said she was taking more of a wait-and-see approach.

"I think Chief Mitchell has been responsive and understands the gravity of the problem now," she said. "It seems like he's off to a good start. I`m not sure the problem has been completely fixed yet, but he has certainly taken some initial steps in that direction."

CAPTION: Superintendent David B. Mitchell said state police have corrected lapses in background checks.