A federal court yesterday turned down a union request to lift an 11-year-old injunction prohibiting strikes, slowdowns or sickouts by the nation's air traffic controllers.

"Strikes by federal employes are substantially more than merely unfair labor practices; they are crimes," U.S. District Judge Thomas C. Platt declared yesterday in New York.

The court action came as administration officials reiterated their intention to prosecute controllers who take part in a threatened strike next Monday by the Professional Air Traffic Controllers Organization (PATCO). Talks aimed at reaching agreement on a new contract broke off Wednesday after PATCO rejected a government proposal that would have given the controllers additional wages and benefits the administration estimates would cost $40 million a year.

PATCO spokeswoman Marcia Feldman dismissed the government's offer as "a very clever move" that would have "only minimal impact on the controller work force." Of particular concern to the union was the proposal to give a 10 percent pay raise for controllers who act as on-the-job training instructors, Feldman said, adding that the provision would allow the Federal Aviation Administration to pick the instructors, thus giving pay boosts to supervisors and staff members whose salaries are now held down by federal pay caps.

She also said the offer was made in a "take-it-or-leave-it style." However, government officials insisted yesterday this wasn't the case. Federal Aviation Administrator J. Lynn Helms told Congress the government isn't willing to raise the total price of the package -- which offers the controllers an aggregate average increase in pay of 11.4 percent -- but it will allow the union to restructure the $40 million package to meet the demands of its unions. Although no further meetings between PATCO and the government were scheduled, Helms told the House Public Works and Transportation subcommittee on investigations and oversight that the FAA was prepared to resume negotiations at any time. "It was the union that walked out," he said.

Helms said the union has had the government proposal since Monday, but has failed to produce a counteroffer and has not told the government what their "bottom line" is, even though pressed to do so by Kenneth Moffett, acting director of the Federal Mediation and Conciliation Service, who is acting as mediator in the dispute.

PATCO President Robert E. Poli said yesterday that he is "willing to realistically compromise on our bargaining positions" but charged that "the intransigence and provocative attitude displayed by FAA" had led to the current situation. "Nobody in this organization wants a strike, but we have been forced into our current position by the absolutely unyielding positions taken by the FAA," Poli wrote in a letter to Rep. Norman Y. Mineta (D-Calif.), chairman of the House aviation subcommittee. "I believe that an act of civil disobedience may well occur if that attitude continues," the letter said.

Still, the government said yesterday that labeling a strike "civil disobedience" won't alter the government's intention to prosecute. "Federal law is very specific about strikes by federal employes," Stuart Schiffer, acting assistant attorney general in charge of the Civil Division of the Justice Department, told the House oversight subcommittee yesterday. "Any concerted job action would constitute a strike." s

Schiffer said material is already in the hands of each of the 96 U.S. attorneys around the nation for use next week in the event of a controllers' walkout.

The administration's position appeared to be greeted with sympathy on Capitol Hill by both Democrats and Republicans. "This Congress will not be intimidated by strikes of this type," oversight subcommittee Chairman Elliott H. Levitas (D-Ga.), told Helms during yesterday's hearing.

Meanwhile, the government and the airlines are bracing for the "worst case condition" in the event of a strike Monday, even though the government continues to believe that not all of PATCO's 14,800 members -- out of a total of 17,000 controllers -- would participate.

But PATCO leaders in some of the FAA's largest regions seemed certain yesterday that a strike would occur. "There is no doubt in my mind that there will be a strike," said David Siegel, PATCO's Atlanta-based southern regional vice president. "The controllers know that they need changes, and many of them feel that this is the only way they are going to get it," he said.

Helms said yesterday that if 20 percent of the controllers fail to show up, not a single flight will be missed. If 50 percent of the controllers walk out, 15 percent to 20 percent of the nation's 14,000 daily scheduled flights would be grounded, with the impact mostly on the shorter flights. If 80 percent of the controllers walk out, "There's no question we're in trouble," he said. About 50 percent of the flights could be accommodated, with priority going to international and transcontinental flights, he said.