AIRLINES

Northwest Files Complaint Against Rival: The Minneapolis-based carrier has asked the federal government to stop American Airlines from using allegedly anti-competitive computer software on its reservation system. In a complaint filed with the Department of Transportation, Northwest Airlines Corp. said the new system blocks out competing flights in violation of a 1984 government rule. Ft. Worth-based American had no immediate comment on the charges. At issue is American’s Sabre Travel Information Network, which is used by travel agents throughout the world.