WICHITA, Kan. (AP) — A federal judge ruled Tuesday that a trial is necessary to decide claims brought against Boeing by two unions over pension and retiree medical benefits arising from the company's 2005 sale of its commercial aircraft operations in Kansas and Oklahoma.

In a 49-page decision, U.S. District Judge Monti Belot rejected for the most part requests by both sides for summary judgment, although he did side with Boeing on some minor claims.

Among issues to be decided is the meaning of "layoffs" as it relates to early retirement and retiree medical benefits stemming from the sale. Belot also ruled that the question of whether Boeing breached its collective bargaining agreements should be decided through trial.

The litigation was first filed in August 2005 by the Society of Professional Engineering Employees in Aerospace stemming from Spirit AeroSystem's purchase earlier that year of Boeing Co.'s commercial aircraft operations in Wichita. The International Association of Machinists and Aerospace Workers joined the case in January 2007. A year later, the court consolidated into the litigation a similar case brought by several workers.

Tuesday's development comes just two weeks after Belot preliminarily approved the voluntary dismissal of all claims against Spirit AeroSystems after the unions agreed there wasn't enough evidence to support the class-action lawsuit over pension benefits. A fairness hearing on that decision is set for June 17.

The plaintiffs continued to pursue their claims against co-defendant Boeing, and the latest ruling means the bulk of those claims will be decided at trial. It has yet to be determined whether a jury or judge will hear the case. Boeing has balked at the union's request for a jury trial, and Belot has ordered the parties to file written arguments on that issue next month.

The case has languished in the federal courts for more than seven years, with filings in it exceeding 500 documents.

In seeking summary judgment, the plaintiffs alleged Boeing breached its collective bargaining agreement by failing to classify all employees as laid off after the sale to Spirit and by amending its pension plan. Boeing argued it should be granted summary judgment because plaintiffs did not go through an administrative grievance procedure before filing suit. The company also contended employees were not laid off as a consequence of the sale.