The arbitrators who created a combined seniority list for the Northwest and Delta airlines pilots rejected the date-of-hire approach favored by Northwest, but they did not simply adopt the solution advocated by Delta pilots.

When merging the lists, the arbitrators placed considerable weight on each pilot's "relative position" on the seniority lists of Northwest and Delta. For example, if a Northwest pilot was ranked in the 20th percentile of seniority in the group of 5,300 Northwest pilots, that pilot would be ranked in the 20th percentile in the combined group, said Andy Murphy, a retired Air Force pilot who owns an airline data analysis company.

The seniority ranking is important because it affects how much a pilot will earn over a career.

In a memo to pilots late Tuesday, the Northwest pilots union merger committee said it was "very disappointed" that the date-of-hire Northwest proposal was not used. The arbitrators' decision "fails to recognize fully the importance of the Northwest pilots' premium jobs on B-747, B-787 and A330 aircraft, the length of service of the pilots and the greater promotional opportunities for Northwest pilots expected to be generated by age-related attrition," the committee said. But the leaders approved of other parts of the decision, including rejection of a Delta proposal to place 400 junior Northwest pilots at the bottom of the list.

Delta had a high rate of retirements a few years ago, so the Northwest pilot group has an older average age.

Lee Moak, chairman of the Delta pilots union, characterized the arbitrators' decision as "fair and equitable."

The award created a special restriction for senior pilots who are flying large airplanes internationally. For five years, Delta pilots will continue to fly Boeing 777s and Northwest pilots will fly Boeing 747s as well as Boeing 787s, which Northwest has on order.

On Tuesday, Minneapolis-based MSP Communications announced that it was selected to publish Sky, the inflight magazine for Delta Air Lines. Delta also signed an agreement to extend a credit card partnership with American Express for five years, which resulted in an immediate payment of $1 billion to Delta.

Liz Fedor • 612-673-7709