A national job-placement company systematically discriminated against blacks in favor of Hispanic workers to comply with racially based criteria of some clients looking for employees, according to allegations in a federal lawsuit filed Tuesday on behalf of several African-Americans.

The lawsuit, filed in U.S. District Court in Chicago, alleges that Personnel Staffing Group LLC used code words to distinguish races and to disguise racially guided decisions, including by using the Spanish word for "bilinguals" to refer to Hispanics.

Personnel Staffing Group LLC, which also goes by MVP and MVP Staffing, has more than 60 offices in nearly 40 states. The lawsuit cites instances of alleged bias by one of its branch offices in the Chicago suburb of Cicero. Multiple messages seeking comment from a head office of Personnel Staffing Group just outside Chicago were not returned.

The 33-page lawsuit was filed on behalf of several African-American laborers, and it names Personnel Staffing Group and seven of its client companies as defendants.

A statement from lawyers and activists announcing the litigation said some companies seek to get around anti-discrimination laws by relying on job-placement agencies. Catherine Ruckelshaus, a general counsel for the National Employment Law Project, said it was akin to companies asking agencies "to launder their overt discrimination."

Discrimination can devastate individuals, as well as their families and communities, added one plaintiff attorneys, Chris Williams, of Workers' Law Office in Chicago.

"It's difficult to imagine a more blatant example of racism than refusing to hire African-Americans based entirely on the color of their skin," he said.

Some companies, the suit said, claimed blacks were more likely to complain about work-safety issues and gave that as one reason for preferring Hispanics. It also says that in instances where African-American got jobs, they were often offered less desirable work. The filing cited one example of blacks working in a hot oven room of a bakery, where some became overwhelmed by the heat and collapsed.