THE BARTER THEATER has been a fixture in tiny Abingdon, Va. (pop. 4,800 at most) for nearly 50 years, starting during the Depression with tickets that cost 35 cents or the equivalent in farm produce. It has a faithful audience, including a handful who have been attending since the first season. They are used to artistic director Rex Partington's folksy pre-curtain welcome speeches, and the nightly prize of a stoneware mug to the person who traveled the longest distance to get to the theater.

Tonight the Barter company will inaugurate its first season in winter residence in Northern Virginia, shifting from an Abingdon building constructed in 1830 to the campus of George Mason University, where a 533-seat theater was built this year. In Abingdon, the audience came from the five states -- Virginia, Kentucky, Tennessee, West Virginia and North Carolina -- that were within busing or driving distance. Here the audience will be drawn from the largely affluent, transient, suburban residents of Fairfax County.

"I'm ambivalent about doing the speech here," Partington said recently during a pause in rehearsals for "The Corn Is Green." "It might be too folksy. I guess all I can do is try and see how it goes over. But I think I've got to drop the longest-distance idea -- with all the diplomats in this area I could get into a real mess."

Moving the company, which operates under an Equity resident theater contract and employs 10 union actors, to this winter home in Fairfax has allowed the theater to operate all year for the first time. In recent years the season has corresponded to the tourist travel months, April to October, and a scaled-down group spent the other months touring schools around the state. It also filled a need for the university, which has a theater and a lot of drama majors, but only three professors and little chance of expanding the theater department. Under the arrangement with Barter, the actors, directors and designers will teach master classes and seminars during the school year.

Partington, who started his career 25 years ago as an actor, has been artistic director of Barter for 10 years, appointed after the death of founder Robert Porterfield. He started his managerial career as an assistant stage manager in New York, working on several Broadway plays, including "My Fair Lady." "That was four years of my life," he said. "But by that time I had young children, and stage managers work a lot more than actors. 'My Fair Lady' enabled me to buy a house in Teaneck, N.J."

He left New York to work for Tyrone Guthrie in Minneapolis as production manager in the early years of the Guthrie Theater, leaving five years later to tour the Midwest with his own production company. Before coming to the Barter he spent several years managing the Cleveland Playhouse. Now he calls Abingdon home; his wife, Cleo Holladay, is a leading actress with the company.

"I would like to see theater people become a respected part of the community, on the level of doctors and lawyers," he said. "That's beginning to happen in Abingdon."

His first season in Fairfax -- "The Corn is Green," "Deathtrap," "On Golden Pond," "Talley's Folly" and "The Heiress" -- was chosen with care and caution, plays to entertain and attract a new audience. Three of the five plays were done by the company in Abingdon, allowing economy in the set and costume budgets. "I want to get more experimental in two or three years, and do plays that may be untried. I don't mean avant-garde, but unknown."

So far, subscriptions are coming in at a rate Partington hoped for. "To sell out we need to get 9,000 subscriptions. I had hoped to have 4,700 by the end of the first play; as of last week we had 3,600, which is right on target." The theater has a budget of about $1 million, of which the state provides about 15 percent, the feds 5 percent, and the box office about 60 percent.

Since its inception, Barter has accepted fruits, vegetables, hams, etc., in lieu of cash for tickets (hence the name Barter). Partington intends to continue this policy in Fairfax.

"But of course," Partington added, "the barter has to be equivalent to the $7 to $10 ticket prices."