The Metro board rejected yesterday a controversial proposal to increase parking fees at most of the subway system's 20 lots.

The plan, defeated on a 3-to-3 tie, had been recommended by Metro officials last week in an attempt to provide an additional $1 million a year in revenue and encourage more commuters to travel to subway stations by bus. Officials said yesterday that further moves to raise parking fees are likely.

Subway riders now pay $1 to $1.25 a day to park at most Metro lots. The proposal had called for increases ranging from 25 cents to 75 cents a day. The current rates have been in effect for five years.

In yesterday's vote, the proposed increases were opposed by board members from Fairfax, Montgomery and Prince George's counties -- areas where most Metro lots are located. District and Arlington County representatives supported the plan.

The Fairfax Board of Supervisors had objected to the proposed increases earlier this week. Fairfax Supervisor Joseph Alexander, a Metro board member, said yesterday that higher fees would be acceptable only if the additional revenue were targeted for expanding Metro's congested lots.

Prince George's County Council member Richard J. Castaldi and Carlton R. Sickles, a Montgomery County member of the Metro board, argued that any increase in parking fees could be viewed as violating the transit authority's pledge not to raise fares this year.

"It would have been a fare increase," said Castaldi.

If parking rates are increased, the two board members contended, the added revenue should be used to subsidize reduced bus fares on routes serving subway stations.

Gladys W. Mack, an aide to D.C. Mayor Marion Barry who heads the Metro board's budget committee, called for further study of the issue.