Metro general manager Richard S. Page yesterday proposed changes in Metro's budget procedures that could cause fares to go up at a greater rate than they have in recent years.

Page, addressing Metro's annual policy conference at Airlie House in Warrenton, Va., called on the Metro board to establish a ratio of fare revenues to subsidies that would be constant from year to year.

To maintain such a ratio, the board would be required to raise fares at the same rate at which operating costs rose. In recent years, costs have risen faster than fares, making Metro more dependent on subsidies.

Some transit officials called Page's proposal impractical, noting that area governments vary widely in ability to pay subsidies and in philosophies of what an equitable sudsidy rate is.

This fiscal year, fares and other revenues are projected to cover about 42 percent of Metro's $339 million operating budget. Subsidies from local, state and federal agencies fund the rest of the budget.

Citing potential ratios of 40, 50 and 55 percent, Page said the board should select one and stick with it. Setting the ratio at 50 percent, he said, would require annual fare increases for the next three years to achieve and maintain the ratio.

Page said that raises required by an operating ratio would not necessarily cut heavily into ridership. "If they are regularly and fairly administered, we can manage the adverse impact on ridership," Page said. At the same time that fares rise, he said, Metro must improve the reliability of its buses and trains.

Metro's current policy is to raise fares about on a par with inflation. But in practice, fare raises are subject to negotiation among the various jurisdictions served by Metro, and are influenced by concerns about ridership loss, ability to pay and public reaction.

D.C. board member Thomas Downs said a single ratio was not practical. Low-income riders in the city need a different level of subsidy than high-income riders in the suburbs, he said.

But Virginia board member Dorothy Grotos said Virginia would favor setting such a ratio. The Arlington County Board is on record favoring fares that cover 75 percent of costs.