Primary voters in Montgomery County chose three conservative and three liberal candidates yesterday to run for three school board seats in November when control of the board will be at stake.

In Prince George's County, 79-year-old Chester A. Whiting was retired from the school board after representing District 3, the Takoma Park-Adelphi area, for 12 years.

Final unofficial results from the District 3 race, the only one in the nonpartisan school board primary, showed Catherine Burch getting 2,583 votes and Malinda Miles 2,362. They will be listed on the November ballot. Whiting trailed with 1,739 votes, and William Flahive came in fourth with 1,277.

The result in Montgomery's nonpartisan primary indicates that the general election this fall will once again be a contest between conservative and liberal philosophies.Conservatives took a 4-to-3 majority on the board in 1978 after a campaign harshly critical of the then-liberal majority.

Incumbent Marion Greenblatt, part of the current conservative board majority, dominated yesterday's returns, getting 52,629 votes, according to unofficial returns.

Following her were liberal incumbent Blair Ewing with 42,878 votes and candidates Suzanne Peyser, with 37,925 votes, Sandra King-Shaw, 33,309, Marilyn Praisner, 30,564, and Michael Goodman, 26,509. The top six vote-getters will appear on the ballot in the fall.

In addition to Greenblatt, Peyser and Goodman are conservatives; King-Shaw and Praisner, like Ewing, are liberals.

Trailing the top six were Edward Gerstenfield, 25,769 votes, Jorge Luis Ribas, 17,099, George Aument, 11,068 and David Roffe 6,930.

In the Montgomery school board campaign two years ago, the conservatives, led by board member Greenblatt, attacked the liberal majority on a broad spectrum of issues ranging from the way it organized the school system to its support of an innovative superintendent, Charles M. Bernardo. The conservatives have made a number of changes in the ensuing years, one of the first being Bernardo's ouster.

In the primary campaign, conservatives defended the recent policies stressing increased discipline, return to "basics" and elimination of many so-called progressive programs.

The liberal candidates generally emphasized the chance to have a more varied curriculum and criticized the board's decision to institute standardized testing.

In Prince George's County, the major issues in Whiting's District 3 contest were his age and his decision to abstain from a recent school board vote to reduce school busing. Both Burch and Miles, the successful primary candidates, said they would have voted against the plan, which is scheduled to be implemented in the fall.

Unlike Montgomery, where all school board members run countywide and serve at-large, Prince George's school board members are elected from individual districts.

Six of the nine Prince George's board seats were up for election, but Whiting's was the only one contested in the primary.

Three of the six board members were automatically reelected when no one filed to run against them.

Along with Burch and Miles, the fall ballot will list incumbent Doris Eugene and Paul Duncan running in District 1 and incumbent Norman H. Saunders and Dow Touchstone in District 9.