A West Chester couple and their office manager pleaded guilty yesterday in federal court in Philadelphia to fraudulently obtaining hundreds of temporary-worker visas for illegal immigrants from Mexico and Central and South America.

Michael Glah, 48, his wife, Theresa Klish, 50, and Mary Gillin, 60, acknowledged under questioning by U.S. District Judge Berle Schiller that between 2003 and 2008 they used names drawn randomly from a Mexican telephone book on falsified visa applications. They then submitted forged documents to the U.S. Department of Labor and coached immigrants to lie to U.S. Citizenship and Immigration Services in order to obtain work permits under the nation's H-2B visa program, which grants 66,000 such permits a year nationwide.

According to the plea agreement read in court by Assistant U.S. Attorney Kevin Brenner, Glah's company, the now-defunct International Personnel Resources, stockpiled visas under fraudulent names. Then, taking advantage of the provision in the law that allows substitutions whenever the original visa grantee becomes unavailable, they distributed them to otherwise ineligible immigrants.

In this way, an illegal immigrant who once worked for a local company but slipped back to Mexico, for example, could come back to work locally with a visa that seemed legitimate.

Glah also pleaded guilty to transporting three illegal aliens into the United States. They were identified in court only by their initials.

Brenner, speaking briefly during a recess, would not say how investigators learned of the scheme.

The ruse was designed to provide local landscaping companies, construction firms, country clubs, and other clients a steady stream of seasonal workers.

The defendants were released on bail pending sentencing on March 29 for Gillin and Glah and April 5 for Klish. They could be sentenced to up to 15 years in prison and fined more than $500,000.

Contact staff writer Michael Matza at 215-854-2541 or mmatza@phillynews.com.