American Airlines and WestJet Enter Codesharing Agreement CheapOair Staff February 28, 2011 general American Airlines & WestJet to Codeshare WestJet and American Airlines came to terms on codesharing Monday. American Airlines will be placing AA codes on WestJet flights to up to 20 Canadian cities not serviced by U.S. airline. WestJet will be placing WS codes on American Airlines flights from Canada to Chicago or Boston. The agreement will allow the airline’s frequent flier members to continue to benefit and build points on the codeshare flights. The deal is currently pending regulatory approval. Source: Dallas News