ANNAPOLIS, JULY 17 -- A joint legislative committee cleared the way today for the state of Maryland to begin random drug testing of more than 15,000 public employees in "sensitive" jobs. Testing positive would be automatic grounds for dismissal, and union officials vowed to fight the plan in court.

With little comment, the Administrative, Executive and Legislative Review Committee declined to act on a series of regulations mandating the tests for workers ranging from psychologists to park rangers.

Personnel Secretary Hilda E. Ford said state officials had anticipated passage of the regulations and are ready to begin the drug tests immediately. However, the plan, among the strictest in the nation, will not officially take effect for two to three weeks and state agencies will have different timetables for implementing it, Ford said.

"It is known very well that illegal drug abuse is a significant problem in our society . . . . Therefore, the responsible thing to do is to act now and to make sure no tragedies occur because we failed to act," Ford said.

Labor leaders urged the committee to recommend amendments limiting the scope of the drug-testing plan, and reacted angrily to the committee's refusal to become involved. Currently, no state worker can be ordered to undergo urinalysis unless there is a reasonable suspicion of drug use and employees who test positive are generally referred for counseling on the first offense.

"I think the committee just passed the buck," said William Bolander, executive director of Maryland Council 92 of the American Federation of State, County and Municipal Employees. "The rules are patently unfair and they know it."

But Sen. James C. Simpson (D-Charles), the committee co-chairman, said legislators were helpless to stop the program initiated by Gov. William Donald Schaefer's administration because under the committee's rules, any vote it might have taken would have been only advisory.

The panel already had asked the governor once to reconsider the plan. But Schaefer was eager to see the plan adopted, making an election year showdown with the governor an unpleasant and futile excercise, Simpson said.

Simpson told union officials that if they are dissatisfied with the program after it is implemented they could bring their complaints to the General Assembly when it convenes next January. Bolander said his organization was unlikely to wait that long, however, and will almost certainly challenge the plan on the grounds that it represents an unconstitutional invasion of workers' privacy.

J. Edward Davis, legal counselor for the Maryland Classified Employees Association, said his organization is particularly offended that the Schaefer administration chose to push the plan without conducting a study to determine what portion of the state's work force has a problem with substance abuse.

The state has already allocated $400,000 to begin the random tests, which will be administered quarterly to about 10 percent of the workers in sensitive positions.

Employees testing positive would automatically be fired. They could not be rehired without a doctor's statement that they had been drug-free for 18 months and completed a rehabilitation program. Workers who lose their jobs after a positive test could appeal through the state's grievance process, but would not receive salaries or benefits while pursuing such an appeal, Ford said.

The regulations define sensitive jobs as those held by workers who have "a substantially significant degree of responsibility for the safety of others and there is a potential that impaired performance of the employee could result in the death of or injury to the employee or another." They also specifically target workers who carry firearms or who are involved in narcotics law enforcement.

Positions identified by state officials include prison guards, driver's license examiners, lottery representatives and warehouse personnel.

Union officials say the definition is overly broad, and Ford said her office is considering reducing the number of positions covered by the plan.