John Alfy Salama Markus worked for the Army Corps of Engineers in Iraq.
Authorities said Salama Markus took bribes from two men who worked with companies seeking U.S. contracts in Iraq. In exchange, Salama Markus provided them with confidential bid and pricing information.
The companies were awarded more than $50 million in contracts.
Authorities said Salama Markus transferred the money from foreign banks to accounts in New Jersey and Pennsylvania.
Officials said he built a $1.1 million house in Pennsylvania with the money.
Salama Markus pleaded guilty to wire fraud, money laundering and failing to file a U.S. Treasury report. He faces up to 35 years in prison and will be sentenced Jan. 8.