Fairfax County's supervisors squirmed uncomfortably yesterday and then decided they would rather be underpaid than unemployed.

The nine-member county board turned down repeated efforts to increase their pay above the $21,589 a year they are scheduled to begin making July 1. The supervisors said no to a proposal to raise their salaries to $25,000; no to another to raise their pay by 3 percent the first year and 5 percent each of the next three years; and no to one that would to raise their pay by 3 percent each year.

"This is so damned awkward," said Supervisor Thomas M. Davis, a Republican from the Mason District, who voted against every pay-raise motion. "I wish we could have some commission or something that would decide it for us."

The supervisors, all of whom are expected to seek reelection this fall, tried to adjourn without taking any action on the politically sensitive issue. But County Executive J. Hamilton Lambert said they had to approve a pay schedule before April 15, the deadline under Virginia law for the board to set its salaries for the next four years.

Supervisor Nancy Falck, a Republican from the Dranesville District, then made a motion to fix the salaries at $21,589 for the next four years. It won on a 6-to-3 vote. Democratic Supervisors Martha V. Pennino of the Centreville District, James M. Scott of Providence, and Joseph Alexander of Lee voted against the proposal, saying their salaries were too low.

"Well, I'm glad the majority of the board seems to be very wealthy," said Alexander, the board's senior supervisor and the leading proponent of higher pay.

Alexander noted during the board's debate that members of the governing bodies in other large jurisdictions in the Washington area make more than Fairfax's supervisors. Council members in the District make $43,480; in Montgomery County, $34,053; and in Prince George's County, $28,963. Fairfax supervisors currently make $20,759. Salaries are lower in Alexandria, $12,500 and Arlington, $10,206, Alexander said.

The Fairfax County Federation of Citizens Associations had urged the supervisors to increase their salaries by $2,500 a year, and Supervisor Audrey Moore, a Democrat from Annandale, who opposed the last pay increase four years ago because it violated the President's cost-of-living guidelines, said a raise this time was justified. "If you can only increase salaries every four years, and you don't, you eventually get to the point where you don't attract good people," she said.

Supervisor Marie B. Travesky, a Republican who represents the Springfield District, agreed that some people who would like to run for office are prevented from running because they could not support their families on the supervisor's pay. But she voted against the pay-raise proposals because the board has capped other county salary increases at between 3 to 5 percent.

"We've got to be realistic," said Travesky. "No amount of rationalizing is going to take away the sting" that county employes would feel if the board voted itself a pay raise.