LOS ANGELES — Striking Hollywood writers and producers openly traded barbs Friday even as the two sides negotiated, with the heated exchanges casting doubt on chances for an imminent settlement of the five-week walkout.

In a letter sent to members and released Friday, the Writers Guild of America accused the Alliance of Motion Picture and Television Producers of dragging its heels in putting new proposals on the table and cited possible schemes to sink the talks.

The alliance, in a rapid-fire response, denied the allegations and claimed the union has failed to respond to its proposals regarding key issues of new-media compensation, instead diverting attention to the proposed unionization of reality TV and animation.

Now in its fifth week, the strike has shut down production on dozens of prime-time and late-night shows, sending a number of programmes into reruns, and has begun to affect film production plans.

Residuals and jurisdiction for online streaming of TV shows and movies, along with other digital distribution, have been seen as the heart of the contract dispute.

Patric Verrone, president of the Writers Guild of America, West, at a guild rally held outside the company that produces the hit TV singing competition "American Idol," told The Associated Press that negotiations were moving very slowly. He questioned the studios' intentions.

"At this point, it's all rumors and conjecture. But we're hearing there are CEOs who are willing to let this television season and the pilot season for next year fall apart," Verrone said, echoing the letter sent out under his name and that of East Coast guild chief Michael Winship.

The guild letter raised what it called "disturbing rumors," including the possibility that one or more of the studios is "prepared to throw away the spring and fall TV season, plus features, and prolong the strike."

"Aside from the devastating effect this would have on the unions, workers and their families in this industry, it would certainly explain the AMPTP's refusal to put any new proposals, even a bad one, on the table," the letter said.

The union also claimed that "highly placed executives" have told some writers that the companies are preparing to abruptly end the talks by accusing the guild of an unwillingness to bargain.

The letter said any such anti-union claims are "absolutely untrue" and challenged studios to negotiate "day and night, through the Christmas and New Year's holidays" to reach a settlement.

An alliance vow to work Thursday night on counteroffers seemed to dissolve when its negotiators were spotted leaving the bargaining site before 7 p.m., "not a promising sign," the guild said in its letter.

The union's remarks reflect its vulnerability, said one observer.

"I think the producers are displaying their leverage quite publicly and aggressively and the writers know it and are fighting back," said Jonathan Handel, an entertainment lawyer at the Los Angeles law firm of TroyGould and a former associate counsel for the guild.

"At the end of the day, the companies have the leverage because they have the money," he said.

In its statement Friday, the alliance said its proposal last week, dubbed the "New Economic Partnership," has yet to draw a direct response from the union. The union has publicly said the proposal offers less than the alliance claims and would constitute a rollback.

In its Friday statement, the alliance alleged that guild negotiators show up late for sessions and "typically spend as much time speaking among themselves" as they do bargaining.

Noting the guild's assertion that it would do whatever it takes to get a deal in place, the alliance contended that union organizers had refused repeated requests to get negotiations started earlier, in spring 2007.

"Had negotiations begun when the producers wanted them to start, perhaps the industry would not now be in the midst of this strike," the alliance said.

Following Wednesday's talks, both sides struck unprecedented notes of optimism. But hopes for progress seemed to unravel Thursday over the issue of union jurisdiction over reality programs.

Producers believed the issue had been taken off the table and were taken aback when it was introduced, according to a person familiar with the negotiations, who spoke on condition of anonymity because they were not authorized to comment.

The union, which said it has responded to the alliance's streaming proposal, said it never agreed to pull reality TV jurisdiction as a bargaining issue.

"Just because there's a central issue (digital distribution), doesn't mean there are other important issues that we can't deal with," Verrone said.

He told the protest rally outside FremantleMedia North America that unless reality shows are unionized, "there will be an army of non-guild workers that will develop and our leverage at the bargaining table will atrophy."

FremantleMedia was declining comment, a security guard at the company said Friday.