Delta Air Lines Inc. has hired Blackstone Group to advise it on a possible bid for the bankrupt parent of American Airlines, and private equity group TPG Capital also is considering a bid for AMR Corp., according to a published report.

The Wall Street Journal also said TPG, which has expertise in the airline business, has approached American parent AMR Corp. about its interest.

AMR filed for bankruptcy in November and is using its Chapter 11 status to cut labor costs - among the industry's highest - and restructure.

It is not clear that either Delta or TPG will close a deal to buy AMR, and even if AMR is sold to one of them, any deal could take months to materialize, according to the Journal.

Blackstone helped Delta reorganize in 2005. Three years later, Delta merged with Northwest Airlines and is now the world's largest airline. American is the nation's third-largest airline by traffic.

In afternoon trading, Delta shares were up 2.8 percent, or 24 cents, to $8.85.