People load picket signs into vans at the Writers Guild of America headquarters in Los Angeles. Hollywood writers will go on strike today against TV networks and movie studios over writers' share of profits from DVDs and the Internet.

Los Angeles ? Hollywood writers will strike after last-ditch talks called by a federal mediator failed.

Writers and studios broke off talks early this morning after East Coast members of the writers union declared they were officially on strike, the group representing producers said.

Last-ditch negotiations between the Writers Guild of America and the Alliance of Motion Picture and Television Producers ended after about 11 hours.

Producers said writers refused a request to “stop the clock” on a planned strike while talks continued.

“It is unfortunate that they choose to take this irresponsible action,” producers said in a statement.

Producers said writers were not willing to compromise on their major demands.

The writers union confirmed that talks had ended and that members would strike, but did not have any further comment.

The guild earlier announced sweeping plans to picket every major studio in Los Angeles, along with Rockefeller Center in New York, where NBC is headquartered.

The Alliance of Motion Picture and Television Producers previously called a writers’ strike “precipitous and irresponsible.”

Taking a harder line

The guilds have been preparing for these negotiations for years, hiring staff with extensive labor union experience, and developing joint strategies and a harder line than producers have seen in decades.

“We haven’t shown particular resolve in past negotiations,” said John Bowman, the WGA’s chief negotiator. “The sea change is that this is an enormously galvanizing issue, and two, that the new regime at the guild actually has a plan, has an organization and a structure to respond to something.”

The writers are the first union to bargain for a new deal this year. Their contract expired Wednesday.

In past years, actors have almost always gone first, although the Directors Guild of America, seen as the least aggressive of the three guilds, has sometimes taken the lead.

Whatever deal was struck first was usually accepted by the others. The guilds are aware that if writers fail to win concessions involving DVDs and the Internet, actors may have to take up the fight.

Consumers are expected to spend $16.4 billion on DVDs this year, according to Adams Media Research. By contrast, studios could generate only $158 million from selling movies online and about $194 million from selling TV shows over the Web, although those numbers are expected to skyrocket in coming years.

Studios argue that it is too early to know how much money they can make from offering entertainment on the Internet, cell phones, iPods and other devices.

1984 decision

Hollywood unions have long regretted a decision made in 1984 to accept a small percentage of home video sales because studios said the technology was untested and that costs were high. Writers only get about 3 cents on a typical DVD retailing for $20.

The guilds have tried and failed for two decades to increase video payments, even as DVDs have become more profitable for studios than box office receipts. Unions say they won’t make the same mistake when it comes to the Internet.

The first casualty of the strike would be late-night talk shows, which are dependent on current events to fuel monologues and other entertainment. Daytime TV, including live talk shows such as “The View” and soap operas, which typically tape about a week’s worth of shows in advance, would be next to feel the impact.

The strike would not immediately have an impact on production of movies or prime-time TV programs. Most studios have stockpiled dozens of movie scripts, and TV shows have enough scripts or completed shows in hand to last until early next year.