He and Mr. Wilkes had been friends in California since childhood  in fact, each had named a child after the other  and his indictment in February 2007 charged that Mr. Foggo had concealed that he had a standing offer of a high-paying job at one of Mr. Wilkes’s companies.

Image Kyle D. Foggo at his arraignment last year. He pleaded guilty to one count Monday. Credit... Lenny Ignelzi/Associated Press

In the statement of facts made public Monday, Mr. Foggo admitted hiding their friendship even as he steered contracts to Mr. Wilkes “through direct and indirect means.”

Mark J. MacDougall, a lawyer for Mr. Foggo, said after the plea was announced, “Mr. Foggo made the difficult decision to bring this case to a close in the best interests of his family and to get on with the rest of his life.”

Sentencing is set for Jan. 8 before Judge James C. Cacheris. Mr. Foggo, initially charged with 28 felony counts, had been scheduled to go to trial on Nov. 3. By pleading guilty to one count, he still faces a maximum penalty of 20 years in prison and a fine of $250,000. But in return for his plea, prosecutors agreed to seek considerably lesser punishment.

His friend Mr. Wilkes built a lucrative business in the 1990s with government contracts he won through connections to powerful members of the House Appropriations Committee. In February, Mr. Wilkes was sentenced to 12 years in prison for bribing Representative Randy Cunningham, Republican of California, who had previously pleaded guilty to corruption charges and is serving an eight-year sentence.