Air France-KLM may play an important strategic or financial role in Delta Air Line Inc's efforts to merge with another airline, The Wall Street Journal reported on Thursday.

According to the sayings of an U.S. congressman on Wednesday, Delta is already in talks with Northwest Airlines Corp and according to some media reports the U.S. airline which operates an expansive domestic and international network is also in negotiations with United Airlines parent UAL Corp.

A report from The Journal said that, according to people familiar with the negotiations, there is a higher probability that Northwest will emerge as Delta's "preferred partner" and that Air France-KLM may support the bid. The support may mean financial help or sweetening a deal and making a rival bid more difficult, while seeking a stake in the combined carrier in return, the report said.

Collaboration already exists between Air France-KLM, Delta and Northwest as part of the SkyTeam, the second largest airline alliance in the world behind Star Alliance. Analysts agree that a merger between Delta and Northwest is more likely to happen and brought up Delta Chief Executive Richard Anderson's past leadership at Northwest to back up their assertion.

Both companies were - Air France and Delta - either unavailable or refused to comment on the issue.