Warren E. Avis, whose name is readily identified with a rent-a-car ("we try harder") business that he no longer owns, has surfaced in the Washington area as a condominium conversion developer - at the Racquet Club near the Beltway and New Hampshire Avenue in Adelphi.

When he was in our town recently to kick off the sales effort for the condominium sales at the highrise apartment building, which he acquired last September, Avis discussed his own life style and interests, which range from real estate investments to a psychological and cultural concept that he calls "shared participation."

Avis is also working with two partners to develop a flower-by-wire service called Tele-Florist. Not unlike the Avis rent-a-car concept, it plans to be No. 2 to the well-established Florists Transworld Delivery system.

A tall, slim veteran of World War II flying and combat intelligence duty, Avis founded his rent-a-car business with $10,000 in 1947 and sold it eight years later for $18 million. Since then he has been buying this and selling that - usually at a profit.

"I try to subdivide my life, almost equally, between business interests, intellectual stimulation and just plain fun," he said. Avis, who has written one book, "The Art of Sharing," and co-authored another, also owns a Ford dealership in the Detroit are.

He has two apartments in New York City, a ville in St. Tropez on the French Riviera, another in Mexico, but considers "Avis Farm" near Ann Arbor his real home. The Avis Research Center is there as well.

The Avis farm also includes a conference center in what once was a farm building and also quarters for seminar participants.

Four years ago Avis bought control of a 11-story Dearborn apartment building that was having financial troubles. He then turned it into what he regards as the "most successful apartment conversion" in the area. Then he bought a townhouse development north of Detroit and spent some money to turn it around.

"We didn't like the way the beautiful view of the Clinton River was hidden by trees and brush, so we cleared away just enough to improve the view without destroying the natural beauty," he told an interviewer. "We expect to have it sold out in one year."

In his condominium work, Avis is applying some of his psychological concepts. He wants the owners of the condo dwellings to be friends.