Blasting television executives for "the virtual absence of Latino images" on network television, a coalition of Hispanic organizations today announced plans for a week-long boycott of the four major television networks.

The so-called "national brownout" is the first step in what Latino leaders meeting here said would be a year-long effort to pressure ABC, CBS, NBC and Fox into casting more Latino actors and placing them in more positive roles. While Latinos make up 11 percent of the U.S. population, not even 1 percent of the lead characters on major network television are Hispanic, a situation made worse by the dearth of Latinos in the networks' upcoming fall lineup, coalition leaders said.

"If these networks don't want to hire us, then we don't have to watch their product," said Alex Nogales, spokesman for the National Hispanic Media Coalition, one of 10 Latino civil rights, professional and community organizations that launched the campaign.

Leaders of the alliance said they are asking Hispanics not to watch any programming on the four major networks during the week beginning Sept. 12.

Announcement of the boycott comes two weeks after the National Association for the Advancement of Colored People lambasted television networks for presenting a shrinking number of black images. NAACP President Kweisi Mfume called for federal hearings on station and network ownership and said the civil rights group plans to closely monitor the TV industry. He also said the NAACP is exploring possible legal and regulatory action against the networks. In addition, Mfume has purchased a small amount of network stock so the NAACP can press for change at shareholder meetings.

Latino leaders attending the annual convention here of the National Council of La Raza (NCLR), the nation's largest Hispanic advocacy organization, said they too plan to explore legal and regulatory action against the networks. They also said they are looking into buying network stock in an effort to turn up the pressure on network executives.

While African American leaders complain about the shrinking number of black roles on prime-time television, Latino leaders point out that they never have established much of a television presence, other than on Spanish-language networks. Moreover, they say, the few Latino roles on the networks are most often stereotypical: gang members, gardeners or nannies.

"Latinos are regular Americans, but we have yet to have that simple fact reflected on television," said Felix R. Sanchez, president of the National Hispanic Foundation for the Arts.

The recent spate of criticism from civil rights groups has prompted network executives to defend themselves by pointing to the minorities on existing programs and showcasing their diversity efforts.

In Pasadena today, ABC Television President Patricia Fili-Krushel said she is committed to "finding lasting solutions to make our network more diverse." ABC has added minority writers, is training minority technicians and stagehands and has worked with NCLR to televise the group's annual entertainment awards show, she said. The network has also said it plans to add minority characters to at least three fall programs.

Similarly, Fox has called diversity a "priority" and said it will add minority characters to the shows in its fall lineup. And NBC today issued a statement reiterating a promise made at a January press briefing that including minority characters is a "top priority."

CBS, meanwhile, has challenged the assertions of the civil rights groups, by citing the relatively high number of minority roles in its prime-time shows.

Staff writer Lisa de Moraes contributed to this story.