A former union leader is a top contender to head the US Federal Aviation Administration, the Wall Street Journal said, citing people close to President-elect Barack Obama's transition team.

Airline consultant Duane Woerth, who was president of the Air Line Pilots Association from 1999 to 2006, has met US House Transportation and Infrastructure Committee Chairman James Oberstar and has his tentative support, people familiar with their discussions told the paper.

But the situation remained fluid, no final decision had been made and other candidates could gain strength, the paper added.

The dynamic also could change if Senate Majority Leader Harry Reid pushed aide Robert Herbert for the FAA post, it said.