The District's budget crisis may force cuts in Metrorail service, meaning riders would wait longer to catch trains that would be more crowded, at the same time that fares are going up 18 percent, D.C. members of the Metro board said yesterday.

District representatives said the city's $300 million deficit will make it difficult to pay the 3 percent increase in Metro subsidies planned for next fiscal year.

They proposed that Metro reduce rail service throughout the system, which it has never done in its 14 years of operation, unlike other big city transit agencies.

One cost-cutting option discussed yesterday would be to reduce the number of trains operating by lengthening the time between arrivals. That means passengers at the busiest stations who now can board rush-hour trains every three minutes might be forced to wait several minutes longer. No changes in bus schedules were proposed.

"If the District gets another big bill for Metro, they may send it back to us and say, 'Take it out of service because the money isn't there,' " board member Gladys W. Mack, of the District, said yesterday at a meeting of the board's budget committee.

Mack and Matthew S. Watson, another District board member, said they were not speaking for Mayor Sharon Pratt Dixon. Efforts to contact Dixon yesterday were unsuccessful.

Longer waits for trains mean that Metro is using fewer trains to carry passengers, which inevitably leads to more crowded cars, Metro officials said.

The agency saves money because it uses less electricity and fewer workers to operate the trains, and doesn't have to spend as much money maintaining the trains because they are traveling fewer miles.

The flip side, however, said Metrorail Manager Fady P. Bassily, is that higher fares and slower service drive away riders.

Metro's ridership already is sagging because of the weak local economy, and transit officials have predicted they could lose as much as 5 percent of their riders as a result of the 18 percent increase in the minimum fare proposed last week in Metro's budget for the fiscal year that begins July 1.

Of the $265 million that local governments contribute to Metro to make up the difference between costs and revenue, the District pays the largest share, about $117 million.

The city's cash-flow crunch this year caused the District to delay its payment and forced Metro to borrow money to pay its bills.

The new Metro budget calls for a 3 percent increase in the local government contributions, and District officials are concerned that the city may not be able to absorb even that modest increase while trying to eliminate its budget deficit.

Watson said the local governments could avoid the increase in their subsidies by raising all fares about 18 percent, cutting spending and reducing service.

Under the proposed fare increase, the minimum rail and bus fare would rise from 85 cents to $1. Budget committee members set out yesterday to figure a structure for the rest of Metro's time- and distance-based fares, but broke up after a lively debate between representatives of the suburban governments and the District over the amount riders should pay.

Committee members from the District and Virginia said they were willing to embrace -- as a starting point for discussion -- a plan for an 18 percent across-the-board increase in fares.

Fares would range from $1 to $3, depending on time of day and distance traveled. The current range is 85 cents to $2.55.

But committee Chairman Cleatus E. Barnett of Montgomery said the Maryland suburbs would resist such increases, because the high fares undoubtedly would drive away hundreds of longer distance Metro riders.

Maryland has the highest number of longer distance riders.

"Why spend $10 billion to build the system and then adopt fare policies that cut it off at its knees?" Barnett said.

Barnett submitted a plan of his own that called for more modest increases for longer distance riders that drew opposition from the District board members, who accused Maryland of trying to make District transit riders pay a larger share of the fare increase.

District officials historically have argued that District riders take shorter trips than suburban riders and thus help subsidize the longer distance riders.

For example, Watson said, under Barnett's plan, the minimum fare would rise about 18 percent, but riders boarding 15 miles from Metro Center would only pay about a 10 percent increase.

Despite the impasse yesterday, Metro board members signaled their intention to raise fares steeply, in part to make up for no increases between 1984 and 1989 despite increased costs.

"We've never advocated an increase of this magnitude," warned board member Joseph Alexander of Fairfax. "I do believe it's going to cause us a lot of trouble."

The only solution, Alexander said, is for Metro to look beyond fares and the local governments as sources of money and to adopt a regional tax, with the revenue dedicated to transportation.