The U.S. Equal Employment Opportunity Commission says it plans to file a lawsuit today against a California-based labor contractor that provided several farms in Hawaii and Washington state with "hundreds of Thai workers" who were "discriminated against as targets of human slavery."

Christine Park-Gonzalez, program analyst for the EEOC in Los Angeles, declined to comment on specifics of the case, since the suit had yet to be filed. She also declined to say in which city the agency would file the suit.

A source said yesterday that the lawsuit will involve Global Horizons Manpower Inc., a company already facing federal charges in Hono­lulu in what has been called the largest forced-labor case prosecuted in U.S. history.

A federal indictment alleges that six Global Horizons employees, including its owner, 45-year-old Mor­de­chai Yosef Orian, and a labor recruiter in Thailand exploited about 600 farmworkers from 2001 to August 2007, holding them in servitude by confiscating their passports, paying them less than promised and threatening to send them back to Thailand.

The workers said they feared going back to Thailand because they took out loans, backed by land and homes as collateral, to pay recruitment fees of up to $26,500.