Nonprofit Gotham arthouse Film Forum has elected media exec Richard Lorber chairman of the board.Lorber and Film Forum director Karen Cooper have upped Film Forum’s endowment campaign goal from $4 million to $6 million. A $1.25 million grant from the Ford Foundation has grown to $2.8 million, giving the theater a jump on the desired sum. Lorber, a board member since 2002, is chairman-CEO of Lorber Media, which includes distrib Koch Lorber Films. Previously, Lorber worked at Fox Lorber Associates, building a library of some 300 titles, including films by Godard and Kurosawa. Lorber will head a board that includes helmer Mira Nair, HBO doc and family chief Sheila Nevins and producer-attorney John Sloss.