Montgomery County Executive Sidney Kramer said yesterday he plans to accelerate his effort to bring Montgomery's volunteer-run firefighting system under tighter county control in light of a recent ruling that could substantially increase the cost of fire protection if the system is unchanged.

The county budgeted $34 million this fiscal year to pay the salaries of 714 career firefighters employed by 18 independent fire companies that include more than 1,000 volunteers. Kramer said yesterday he will submit "emergency legislation" to the County Council on Thursday, to have the firefighters classified as county employes.

U.S. District Judge Herbert Murray ruled July 30 that the fire companies are private entities. Citing the federal Fair Labor Standards Act, Murray said the paid firefighters, as employes of private entities, must receive overtime pay when they work more than 40 hours in a week.

However, if the firefighters were classified as county workers they would be considered public employes under federal labor law and would receive overtime pay only after working 53 hours a week, Kramer said. He said most of them currently work 48 hours a week.

Murray has not calculated an overtime pay rate for the firefighters, if they remain employes of the private fire companies. The judge has several formulas from which to choose, Robert K. Kendal, director of the county's Office of Management and Budget, said last night.

Depending on which formula the judge uses, Kendal said, overtime pay could cost the county between $1.4 million and $6.1 million in the next year if the firefighters are not made public employes.

Edmond Rovner, a special assistant to Kramer, said Murray also has ordered retroactive overtime pay for firefighters, but has not decided on the number of past years or a formula to use in calculating the overtime pay rate. Based on the options available to the judge, Kendal said, the figure could range from $6.3 million to $24 million.

Kramer said he had planned to wait several weeks before asking the council to classify the firefighters as county employes, as part of a broad reorganization recommended in a 41-page report issued July 29 by a commission that studied the firefighting system. It recommended creating a countywide fire department to oversee the volunteer companies.

Realizing the implications of Murray's ruling, Kramer said, he decided to move sooner to bring the firefighters under county control. If the council agrees to consider his proposal, Kramer said, a vote will not come until after a public hearing next month.

In the meantime, Kramer, in a memorandum yesterday, urged leaders of the volunteer fire companies to make the best use of their paid personnel. He suggested they reschedule firefighters' vacations and take other steps to keep as many of them as possible on the job, limiting the need for overtime until the council acts on his proposal.

In an interview, Kramer said he plans to propose in September or October that the council adopt the rest of the recommendations contained in the July 29 commission report. The panel envisioned a countywide fire department, with improved training and recruitment procedures and one fire chief controlling the deployment of personnel and equipment.