Transit specialists in area local governments, concerned over escalating subsidy bills for Metro's buses and trains, want to cut $32 million from the $365-million budget proposed by the transit system's staff for fiscal 1983, the Metro board's budget committee was told yesterday.

The reduction plan will be made public next month. But sources said much of it would focus on programs that Metro planners say would improve reliability and cleanliness and rally stagnating ridership. Their counterparts in local governments counter that Metro is under severe financial strain and should be content to keep service at current levels.

Addressing the budget committee, Maryland Department of Transportation official Mort Weinberg cited fear that ridership could fall short of the 1.3 percent growth that Metro has projected for fiscal 1983, creating a further squeeze on revenue. Weinberg heads an ad hoc budget committee of state and local government staff.

The decline in gasoline prices--which encourages use of private cars--and continuing high unemployment could undo those predictions, he said.

His statements came as Metro released figures showing a slight drop in rail ridership in December. The Red Line was opened through to Van Ness that month and Metro had expected an upswing. Though the three new stations were busier than expected, ridership in the rail system as a whole declined. Officials had no explanation for it.

Local governments criticize Metro's budget every year. But pressure to save money is particularly strong today, as federal operating aid that covers eight percent of Metro's costs is about to be phased out and costs continue to rise well ahead of farebox revenues.

The draft budget, released by Metro General Manager Richard S. Page last December, calls for the transit system's eight local governments to provide at least $206 million for operating subsidies and debt payments, a 35 percent increase over their expected bills this year.

Responding to Weinberg's statements, General Manager Page said his staff had found ways to cut up to $12 million since the budget was drawn up last fall, mostly thanks to lower-than-expected expenses for fuel and cost-of-living raises for Metro employes.

But cutting more would mean "significantly reducing the level of service" in the jurisdictions that are demanding the cuts, Page said.

Among cuts being proposed by the local governments, according to one Metro staff member: $2 million less for spare parts; $1 million less for electricity to light and run Metro stations and other facilities; $3.4 million less in salaries and benefits by delaying the filling of vacant jobs.

Metro officials hold that such steps could cripple efforts to attract new riders and help stop the steady erosion in Metro's ability to pay for itself. Fares now cover less than half of Metro's operating costs.

In other Metro developments yesterday:

The board gave final approval to a $1-million plan to equip 50 to 60 more buses with wheelchair lifts and create a "reservation system" which would allow disabled passengers to telephone in advance to assure a lift-equipped bus would be on their route when they want to travel.

The board authorized the staff to apply for $10 million in federal grants to rebuild about 150 aging General Motors buses, the first step in a plan to redo 600 old buses by mid-decade.

The board was told that the D.C. City Council opposes shifting funds intended for Green Line construction in Anacostia to other subway sites. A federal judge has halted the Anacostia project until D.C. conducts new public hearings on the Green Line's alignment.