JPMorgan Chase executives discussed downgrading their internal credit rating for Tribune Co. just hours after the media company completed a leveraged buyout the bank helped finance.

E-mails presented in federal court in Wilmington, Del., Wednesday show an executive for the bank thought a downgrade was required after the buyout.

Lawyers for some creditors who object to Tribune’s bankruptcy reorganization plan are trying to show the bank had serious concerns about Tribune’s finances at the time of the buyout. Some creditors claim the deal was a fraud.

The 2007 buyout saddled Tribune with more than $12 billion in debt. The company filed for bankruptcy protection less than a year later. A court-appointed examiner has concluded that parts of the buyout probably constituted fraud.