Law enforcement officials, trying to keep pace with well-heeled criminals who have turned to car phones and faxes to conduct their business, asked state and federal judges last year for 763 wiretaps at an average cost of $53,108, according to a report by the Administrative Office of the U.S. Courts.

Federal operations, which account for more than 40 percent of the requests, racked up a per-investigation tab of $80,685, with one wiretap in a New York drug case lasting 263 days and costing $902,475.

"In today's world of highly advanced electronics, it is no surprise that even small-scale crime organizations use cellular telephones, paging devices and facsimile machines," L. Ralph Mecham, director of the administrative office, said in the report.

"In turn, law enforcement agencies also take advantage of highly sophisticated surveillance equipment to obtain incriminating evidence, especially involving large-scale organized crime organizations," Mecham said.

The annual report, required by the 1968 Omnibus Crime Control and Safe Streets Act, listed the alleged crime, the numbers of days the surveillance was in operation, the resulting arrests, and the cost of every wiretap approved by a state or federal judge in 1989.

While the taps have grown increasingly expensive, they have also reaped greater results, according to the study.

In 1989, 2,804 people were arrested as a result of all modes of electronic surveillance, 706 of whom were convicted before the year was out. A state phone intercept in Delaware resulted in the seizure of $657,000 in cash, 270 pounds of marijuana, 2.5 pounds of cocaine, six weapons and four vehicles, the report said.

Not surprisingly, drug investigations account for the bulk of the approved taps. More than 60 percent of the wiretaps eavesdropped on drug organizations, with gambling setups ranking second with 15 percent of the taps and racketeering responsible for 12 percent of the electronic bugging.

Three electronic surveillances were approved by federal judges in the District -- one for a bribery investigation and two for narcotics. The report noted that 30 arrests were made last year in one of the cases, on which law enforcement officials spent $106,000 to secretly monitor the drug organization for 117 days.

Federal judges in Maryland approved 14 taps for a variety of drug and racketeering cases, resulting in 91 arrests last year. The 10 clandestine operations in Virginia returned 24 arrests in the year.

The report said that the complexity of the cases often means that arrests are not made until the calendar year after the issued wiretaps. During 1989, there were 1,361 arrests, 1,829 convictions and additional costs of $576,000 resulting from wiretaps conducted in previous years.

Thirty-seven jurisdictions, including the federal government, the District, Puerto Rico and 34 states, allow wire, oral or elecronic surveillance. During 1989, 25 of those used at least one of the methods, according to the report.

All 763 applications before state and federal judges were approved. More than 40 percent of the wiretaps were conducted in single-family dwellings, and 48 percent of the taps authorized by state courts were issued in New York and New Jersey.