A former American occupation official in Iraq is expected to plead guilty to bribery, conspiracy, money laundering and other charges in federal court on Thursday for his actions in a scheme to use sexual favors, jewelry and millions of dollars in cash to steer reconstruction work to a corrupt contractor, according to papers filed with the court.

The official, Robert J. Stein Jr., served as a comptroller and funding officer in 2003 and 2004 for the Coalition Provisional Authority, which governed Iraq after the American-led invasion. Four Americans, including Mr. Stein and the contractor, Philip H. Bloom, have been arrested in the case. Mr. Stein's plea, apparently with the understanding that he will cooperate with prosecutors, is the first to be made public.

The court papers depict a sordid exercise in greed and corruption that was spread much more widely that previously known. Including the four people already arrested, the papers indicate that a minimum of three other still unnamed co-conspirators also played a role in the scheme. In order to give more than $8 million in contracts and millions more in stolen cash to Mr. Bloom, the papers say, the conspirators accepted bribes, valuable goods and other favors.

Two of the Americans already arrested, Lt. Col. Debra Harrison and Lt. Col. Michael Wheeler, are senior Army reserve officers. The court papers indicate that the remaining unnamed co-conspirators are also Army reserve officers, for a total of at least five officers involved. But the papers suggest that others, identified only by opaque designations like "person H," may also have been involved in one way or another.