Travelers at BWI Thurgood Marshall airport could be buying tickets to Europe from Southwest Airlines by 2010, according to the carrier's CEO, Gary Kelly.

Speaking at a meeting of the BWI Business Partnership Monday, Mr. Kelly said Dallas-based Southwest would most likely offer flights to Europe using a "code-sharing" agreement with a current international carrier. Code-sharing would allow Southwest to sell tickets but rely on another carrier to provide the actual planes and flights. Southwest - which soared to fame on low-cost, all-domestic flights - hopes to begin the first phase of its international service by adding routes to...