Executives from Mr. Letterman's company said Saturday that they are hopeful they will have an interim agreement in place with the guild as early as this week. That could potentially put Mr. Letterman at an enormous advantage over most of his late-night colleagues.

Jon Stewart of Comedy Central's "Daily Show" has also been urging an interim agreement and would begin working toward getting one in place the first thing Monday morning, according to a representative. But Mr. Letterman is in a stronger position because, unlike Mr. Stewart, his show is not owned by a network but by Mr. Letterman's independent production company, World Wide Pants. (So is the show that follows it on CBS, "The Late Late Show with Craig Ferguson," which would return with writers under the proposed interim agreement.)

The news of Mr. Letterman's potential deal came at the same time the union took a new tack that could potentially throw the negotiations into procedural chaos. The writers' representatives said they planned on Monday to exercise a legal right to insist that the major studios and network production companies bargain with the guild individually rather than as a group. In a letter sent to members on Saturday, negotiators for the Writers Guild of America East and the Writers Guild of America West said: "Each signatory employer is required to bargain with us individually if we make a legal demand that it do so. We will make this demand on Monday."

The writers' move was aimed at breaking what has been, at least in public, a united front by a small number of media conglomerates - General Electric, News Corporation, Sony, Time Warner, The Walt Disney Company, Viacom and CBS - whose entertainment units dominate the Alliance of Motion Picture and Television Producers, an industry bargaining group. In a statement, the producers alliance immediately dismissed the move as "grasping for straws." J. Nicholas Counter III, president of the the alliance, said in an interview that his group remains the bargaining agent for each of the represented companies, whether they proceed individually or together.