Controversy over pension language in the Federal Aviation Administration reauthorization bill sparked a rift this week between two prominent Democratic Senators: Majority Whip Dick Durbin (Ill.) and Finance Chairman Max Baucus (Mont.).

The sparring forced Democrats to delay a floor vote on yet another bill that was expected to be relatively noncontroversial.

Baucus and Durbin were seen in a heated exchange Wednesday afternoon outside the Senate chamber after arguing on the floor for most of the day over a controversial provision to require airline companies to contribute to their pension plans, regardless of their financial situations.

Late Wednesday, Senate Majority Leader Harry Reid (D-Nev.) intervened to strip that language from the legislation, which will allow the bill to move ahead to a floor vote.

Earlier Wednesday, Durbin, along with Sen. Kay Bailey Hutchison (R-Texas), had offered an amendment that would have removed language requiring certain airline companies to pay $2 billion into their pension plans over five years.

That afternoon, Durbin ran from the Senate chamber after Baucus, stopping him in the hallway. Durbin pointed his finger and could be heard heatedly saying, “This is personal,” several times to his Democratic colleague.

Baucus had earlier criticized the Durbin amendment for giving an additional break to airline companies that are not in dire need of assistance or facing bankruptcy. He said the the Durbin amendment would create an unfair playing field — allowing some airline companies to forgo their responsibility to pay into their pension funds.

“The effect of the committee bill is to level things off. It’s not perfect, but it’s almost perfect,” Baucus said.

“Where the effect of the Durbin amendment is to make it much less perfect and help a couple of airlines who, as a consequence, will not have to contribute to their pension plans for past liabilities and will not have to in the future because of the interest rate they provide for in their amendment,” Baucus said on the Senate floor.

However, Durbin countered that under the pension language in the aviation bill and supported by the Finance chairman, certain airlines are receiving preferential treatment and allowed to freeze payments to their retirement plans, while other companies are experiencing financial problems but are still required to fund their pensions.

Durbin cited Northwest Airlines and Delta as the two companies getting special treatment in the FAA bill, while airlines such as American are experiencing problems but are forced to pay pensions.

“It seems like it’s upside down,” the Majority Whip said. “You would think we would be benefiting those companies that are trying to do better by their employees, but instead we went the other way.”

The original bill pitted the Commerce, Science and Transportation Committee against the Finance Committee in trying to come up with an FAA modernization plan.

Sen. Jay Rockefeller (D-W.Va.), who sits on both committees and chairs the Commerce Subcommittee on Aviation Operations, Safety and Security, relented on his proposal to fund the aviation modernization project with an increased airline gasoline tax, instead of his earlier suggestion of a surcharge on tickets.