Japan Air System Co. has signed an agreement for opening comprehensive business cooperation with KLM Royal Dutch Airlines to strengthen the two carriers' competitiveness between Japan and Europe.The two airlines exchanged a memorandum of understanding at KLM's headquarters in Holland on Oct. 23, a JAS spokesman said Oct. 24. The two firms plan to start a mileage program in February, pending approval from the Transport Ministry.Under the pact, they will expand cooperation in marketing, flight connections, check-in services, code sharing and luggage handling. They also will examine the possibility of cooperating in information systems, operations and maintenance.