Federal prosecutors have charged a Chester County personnel firm with fraudulently obtaining temporary visas and allowing "thousands" of workers to enter the country with illegal documents.

Names were randomly selected from Mexican telephone books to fill out the visa paperwork, said First Assistant U.S. Attorney Virginia Gibson.

Michael Glah, 48, the owner of International Personnel Resources in West Chester, allegedly took advantage of a government program that provides 66,000 seasonal visas a year, mostly for people in agriculture and landscaping. Prosecutors charged that Glah's company stockpiled visas under fraudulent names, and when a local firm needed any employee, they could get the visa and change the name to the actual person.

IPR charged $600 to $1,000 per worker.

The investigation into local companies that obtained visas from IPR is continuing, said Assistant U.S. Attorney Richard Goldberg.

Glah and three co-workers were charged in an "information," which typically suggests they are cooperating with the government.

The information cites about 450 specific individuals who illegally entered the country, but Edgar Moreno, an official with the Department of State's Bureau of Diplomatic Security, said the scheme had been in operation for much of the decade, and provided "thousands" of illegal visas.