LORIMAR CHAIRMAN TO WED BARBARA WALTERS

TV interviewer Barbara Walters, who usually asks the questions, answers one tonight, when she says “I do” to Merv Adelson, the TV executive who helps bring romance to Middle America, friends said Friday.

Adelson, head of Lorimar--which produces “Dallas,” “Falcon Crest” and “Knots Landing”--will marry the ABC newscaster this evening at a gated estate at the edge of Beverly Hills.

Although the couple have been engaged for almost a year, friends say that the decision to marry this weekend was made just this week. The original guest list was at 30, friends say, but then Walters got on the phone and invited 50 friends from New York and here.

The wedding is reported by friends to be a traditional Jewish ceremony, to be held after sundown, the end of the Jewish sabbath. Appetizers, including baby hamburgers and nachos, will be served before the ceremony. A chuppah-- a bridal canopy--will be erected inside the home, friends said, where the exchange of vows will take place. The dinner party following the service will be held in a tent in the backyard, with the food catered by Chasen’s, reportedly including baked potatoes with caviar, veal, Brie cheese, and a wedding cake.

Adelson, 56, is chairman of the board of Lorimar Productions and, since 1963, president of Rancho La Costa; Walters is 54 and has been a star newscaster personality for ABC-TV for 10 years. Both have been married before.