Gates ordered Deputy Secretary William Lynn in December to review the military's practice of paying retired officers hundreds of dollars an hour to act as "senior mentors," helping run war games and advising active-duty officers.

Lynn has completed the review and will present his recommendations to Gates, Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, and the chiefs of the military services, Pentagon press secretary Geoff Morrell said.

Gates was responding to a USA TODAY investigation, which reported that most of the mentors had ties to defense contractors and that there were few ethics rules governing potential conflicts of interest. The newspaper reported that some mentors were earning more as advisers than they did as active-duty generals, even as they collected six-figure pensions and consulted with defense companies seeking Pentagon contracts.

In the months leading up to the review, Gates has expressed concern about mentors' pay, which can reach $486 an hour. Mullen said in November that mentors must avoid even the appearance of a conflict of interest.