A federal appeals court has ordered federal officials to allow Continental Airlines to fly a Seattle-Tokyo route, reversing a government decision giving the route to United Airlines.

The route was controlled by Pan American until it sold its Pacific business to United Airlines. The Department of Transportation then declared the Seattle-Tokyo route open.Federal aviation officials in June 1987 awarded Continental the route but then reconsidered and awarded the route to United. Continental went to court, finally overturning the decision in both federal and Washington, D.C., appeals courts.

"We are extremely pleased by this decision, which we believe reaffirms the original principles upon which the case was first decided," said Continental President Martin R. Shugrue.

Continental expects to begin service on the route next year. The carrier currently serves Tokyo and three other Japanese cities via its mid-Pacific hub in Guam.

"This northern route segment completes Continental's circle around the Pacific, and further develops our large and successful international route network," Shugrue said.

In Elk Grove Village, Ill., United Airlines officials criticized the decision and suggested the airline may appeal.

"The Department of Transportation, which is charged with the responsibility of deciding which carrier is best suited to operate a route in public interest, had determined on the merits that United Airlines should retain its Seattle-Tokyo route," said Rob Doughty, manager of external communications.