Labor cooperation is crucial to the success of a Delta-Northwest combination. Last year, Delta pilots helped the airline defeat a hostile bid from US Airways to acquire the airline while it was in bankruptcy.

Negotiations between Delta and Northwest executives are focused on how to build a unified seniority list for the 11,000 pilots at both airlines.

Without an agreement beforehand, negotiations with the pilots represented by the Air Line Pilots Association over seniority could drag on for years, The Wall Street Journal has reported in its online edition.

Such a list is crucial to pilots because it determines nearly everything about their professional livelihood, from pay to assignments.

"I've heard rumors up to and including the fact that [leaders of ALPA's Delta and Northwest chapters] are already trying to figure out the seniority," Mike Dunn, a Salt Lake City-based pilot who flies for Delta, said Monday. "That tells me they are pretty far along."

Delta and Northwest have shared details of a proposed merger with ALPA officials, Bloomberg News said Monday, citing people familiar with the talks.

Kelly Regus, a spokeswoman for the pilots union, said ALPA would not comment.

Although the union has a nonvoting member on Delta's board of directors to guard the interest of pilots, ALPA's Delta chapter has said nothing to members other than it will not support a merger unless it benefits pilots and the company, Dunn said.

Dunn is one of 600 pilots stationed at Delta's airport hub in Salt Lake City. He said talk that a common seniority list might be reached without contributions from rank-and-file members terrifies pilots.

"When you merge two companies, your relative seniority in the merged company determines where you live, what you fly and ultimately what you get paid. We are curious how this will all work out," Dunn said.

Seniority also ties pilots to an airline. Pilots who quit cannot carry their seniority to another carrier.

pbeebe@sltrib.com