SAN DIEGO, Dec. 15 (UPI) -- The president and vice president of a California fence company face at least six months in prison after pleading guilty to hiring illegal immigrants.

In a plea bargain reached with prosecutors, Riverside-based Golden State Fence Co. has agreed to forfeit $4.7 million in what federal officials say is the largest penalty ever brought against an employer in this type of criminal prosecution, The San Diego Union-Tribune reports.

Golden State and two of its executives admitted in federal court in San Diego on Thursday that they repeatedly hired undocumented workers deported after immigration raids even though authorities warned them not to.

Under terms of the plea agreement, the company's president and vice president will avoid a sentence of five years in prison and instead face at least six months of incarceration.

Sentencing is scheduled for March 28th.