Metro's board yesterday asked passengers, who take about a million bus and rail trips a day, to tell the board whether they support a proposal to raise fares an average of 18 percent starting in late June.

The proposed increases, which would raise the minimum fare from 85 cents to $1 and the maximum fare from $2.55 to $3.15, have the board's tentative approval with the understanding that the plan is only a starting point for public debate.

A final decision will be made after a series of six public hearings in March and April, two each in the District, Maryland and Virginia.

By then, the board will have a new general manager. It is expected to be David L. Gunn, the former director of the New York City Transit Authority. Gunn has been offered the job, sources said, and is involved in last-minute negotiations with the board.

Gunn, contacted this week, would not confirm whether he has accepted the Metro job.

The fare proposal would raise about $40 million a year for the regional transit system, which is undergoing a period of financial trouble brought on by the economic downturn, higher fuel costs and slow ridership growth. The board is asking that a larger share of the agency's costs be borne by riders instead of the local governments, which are having financial problems of their own.

"Giving consideration to fare increases isn't an easy decision," said board member Gladys W. Mack, of the District. "But in view of the authority's needs and the financial constraints on local governments, additional revenue from passengers is going to be necessary in the next fiscal year."

In a short discussion, new board member Hilda R. Pemberton, of Prince George's County, said the board should look more carefully at cutting spending before adopting large fare increases.

Board Chairman Hilda H.M. Mason, of the District, reiterated her longstanding belief that all taxpayers should pay for Metro so that the system's users can ride for free.

"It's public transportation and it should be public," she said.

The fare increase proposal is unpopular with virtually all board members. A basic sticking point is over whether suburban riders should pay proportionately higher fares than District riders.