The pleas came 10 months after federal agents staged sweeping raids at 40 IFCO Systems sites in 26 states. More than 1,100 people were arrested on administrative immigration charges in the April raids, according to Sid Siders, supervisory special agent for the federal Immigration and Customs Enforcement (ICE) in Utah. Thirteen workers were arrested at an IFCO Systems workplace in Tooele.

The managers hired the undocumented foreign workers, mostly Mexicans, as a competitive advantage and withheld benefits and overtime from them, federal prosecutors said.

''These are management-level people that it is fair to say were employing this as a business practice, hiring illegal aliens,'' said U.S. Attorney Glenn Suddaby.

James Rice, 37, of Houston, an executive regional general manager of the Netherlands-based IFCO Systems, pleaded guilty to conspiring to employ illegal workers. Robert Belvin, 43, of Stuart, Fla., a former general manager of the Albany IFCO plant, pleaded guilty to two felony conspiracy charges.

The two executives could face up to two years in prison and a $250,000 fine, Assistant U.S. Attorney Tina Sciocchetti said.

Defense lawyers said they reviewed prosecution material that included taped conversations involving their clients.

''Under the circumstances, we thought the only rational thing to do was to plead guilty,'' said Belvin's lawyer, Terence Kindlon.

Dario Salzano, 36, of Amsterdam, N.Y., Scott Dodge, 44, of Elmira, N.Y., and Michael Ames, 44, of Shrewsbury, Mass., each pleaded guilty Tuesday to one misdemeanor. They could face up to six months in jail and $3,000 in fines for each undocumented worker employed, though they likely will get reduced terms because they cooperated, Sciocchetti said.

Charges were pending against two other IFCO managers in Houston and Cincinnati.

IFCO said in a statement that it was not corporate strategy to hire undocumented workers. After the raids, the company reviewed its employees and enrolled in a federal screening program for workers.