If you expected the doors to open on the sixth annual Washington Art Fair this month, as they have every spring for the past five years, don't wait anymore. WASHART has been postponed until September and Washington seems to have lost an important round to Chicago in the ongoing battle of the art fairs.

"It's a purely pragmatic decision," says WASHART founder and organizer Eli Felluss, who has also put on fairs in Los Angeles. "The top-rung dealers are going to the new Chicago fair [May 14 to 19] and the bottom-rung dealers have been going to the New York print fair in March 1. I was left sitting right in the middle, so I decided to move WASHART '81 to the beginning of the new season next year.

"There's been a split in Fair ideology," explains Felluss, who modeled WASHART -- the first American art fair -- on the Basel Fair, which has taken place in Switzerland each June for the past dozen years and is still the big daddy of the many European art fairs. "Basel was a broad-spectrum fair, from the top-notch to the lower-rung, and that's what I envisioned for Washaington. I've managed to do it for five years, but this year -- largely due to the conflict with Chicago -- there were just not enough top dealers signed up to make this the kind of show I wanted." Felluss suggested that borad-spectrum fairs may no longer be viable.

Three Washington dealers -- Jane Haslem, Harry Lunn and Diane Brown -- were enthusiastically packing up their wares last week in preparation for the trip to Chicago's Navy Pier. "I don't want to badmouth WASHART," said sculpture dealer Brown, "but I'm going to Chicago because, for one thing, it's a juried show, which ensures high quality, and I want to expose my sculptors to other good markets -- and expose other good markets to me. The Chicago fair is only two years old, but it's already established itself as the most important fair, and they've got dealers banging down the doors. Lots of people didn't get in."