LOS ANGELES, Nov. 21 (Xinhua) -- The ongoing strike by Hollywood screenwriters would leave thousands of people jobless and have a huge impact on the Los Angeles area's economy, local officials have warned as the strike received more support and no signs showed it will end soon.

As thousands of TV and film writers marched in Hollywood in the third week of their struggle, film officials put a price tag on the potential economic toll of the walkout.

According to Film L.A. Inc., the nonprofit group that handles film permits and promotes the entertainment industry in the area, local economy will lose more than 20 million dollars a day in direct production spending if the writers strike extends into next month.

"If the strike continues it's going to have a huge impact on the local economy and middle-class jobs," said Steve MacDonald, president of Film L.A., told the Los Angeles Times Wednesday.

About 12,000 members of the Writers Guild of America walked out earlier this month in a dispute with major studios over pay for work that is distributed via the Internet, video iPods, mobile phones and other new media.

Writers and major studios are expected to resume talks next week, although the writers union has vowed to continue striking until a deal is finalized.

Striking writers were joined in Hollywood Tuesday afternoon by members of such unions as the Screen Actors Guild, Teamsters and Service Employees International Union. Union officials said the solidarity march drew about 4,000 people.

Depending on how long it lasts, the strike could end up inflicting more economic pain than the previous writers walkout in 1988, which lasted 22 weeks and cost the entertainment industry some 500 million dollars. That was the equivalent of a little more than 3 million dollars a day.

The entertainment industry is a more dominant force in Los Angeles' economy today, with studios and networks that are part of global media giants such as Time Warner, Walt Disney and News Corp. The area is also more dependent than ever on television production, which has taken the biggest hit in the strike.

Meanwhile, the current walkout occurred in the middle of the fall TV season, before networks had a chance to stockpile all the scripts they needed. At least two dozen shows have already stopped production, including late-nights talk shows and drama series like Fox's "24," ABC's "Desperate Housewives," and NBC's "The Office."

If the strike continues into next month, it would translate into a loss of 15,000 jobs and 21.3 million a day in direct spending, according to estimates by Film L.A.

Officials said their estimate is conservative because it only takes into account jobs in the industry, not the scores of jobs at restaurants, hotels and other businesses that service Hollywood. The entertainment industry accounts for almost 7 percent of the Los Angeles area's economy.