Iraq has an estimated 9 percent of the world’s crude oil, but its pipelines and other infrastructure are aging. Many of its most productive fields, laced with water because of mismanagement, are no longer able to produce as much oil as they once did. The country lacks the money to rebuild the industry, which accounts for almost all of its foreign earnings.

The auction on Tuesday, held in a heavily secured ballroom at the Rashid Hotel in Baghdad’s Green Zone, was reminiscent of a professional sports draft lottery. Bids were placed inside a large plastic box that had been set up on a stage. The oil companies were given 20 minutes to mull over each oil and gas field, with the time shown counting down on a giant video screen.

The sight of executives walking onstage to drop sealed bids in the plastic box brought cheers of delight from Oil Ministry employees in the audience.

The executives themselves, representing Exxon Mobil, Lukoil, Japex, Royal Dutch Shell, Total and the Korea Gas Corporation, among others, then stood aside as their offers were displayed on a screen before the bids were compared to those of rival companies seeking the same contract.

The Oil Ministry said it chose to conduct its business on television and in front of an audience of reporters and others to combat allegations of widespread corruption in the ministry, which led it to cancel a group of no-bid oil contracts last year. Major oil companies had little interest in the terms of those contracts, either.

Because the financial risk of a 20-year investment in Iraq was considered to be too great for even the largest oil corporations, the companies for the most part formed joint ventures.

Throughout the day, clusters of men in dark suits spoke to each other in their common language: broken English, with Dutch, Chinese, Russian and Thai accents. A member of a Korean delegation wore a flak vest inside the hotel ballroom.