The major hotel workers union launched a campaign yesterday designed to narrow the wage gap between workers in various states, pointing out that hospitality employees in highly unionized areas make more than double those in less-unionized areas.

Unite Here, the result of two unions that merged in 2004, mainly represents workers employed by the operating companies that own the majority of hotels in the nation, including Hilton Hotels Corp., Hyatt Corp., Marriott International Inc. and Starwood Hotels & Resorts Worldwide Inc. The union represented Washington workers in a contract dispute last year.

John Wilhelm, president of the hospitality division of the union, said his group has recruited actor and activist Danny Glover and former senator John Edwards to join in the campaign, dubbed Hotel Workers Rising.

The push, he said, "involves bringing all those folks together to say to those hotel companies that everyone would be better off if they brought about middle-class jobs in whole industry."

Wilhelm, calling unions "our most effective anti-poverty campaign," said the average wage of a hotel worker in a city that is "lightly unionized," such as Phoenix, is $7 to $8, while a hotel worker in a highly organized city such as New York earns about $18 to $19 an hour. The cost of living in Phoenix is lower than in New York. The union hopes its effort will result in getting workers on similar wage and benefit scales.

Simultaneously, the campaign asks workers in union cities such as New York to flex their muscle and persuade hoteliers in less-unionized areas to improve employee working conditions.

The union, considered to be among the most outspoken and creative in its organizing and negotiating efforts, engineered contracts among hotel chains in major cities to expire at the same to gain more bargaining power.

The simultaneous expiration creates a threat of strikes that could occur in many cities at once. That possibility puts greater pressure on the companies to provide higher wages and more benefits and job protection.

Major contracts expire this year in Toronto, New York, Los Angeles, Boston, Honolulu and Chicago. San Francisco workers have been without a contract since last year.

The tactic could be effective for a hotel workers union that is "dealing increasingly with large transnational chains . . . that have the resources to weather the storm," said Harley Shaiken, a labor professor at the University of California at Berkeley. But by expanding its "economic reach," he said, the union can increase pressure on employers.