Originally Posted by mezzanine
my bad. I'm not sure if WJ has any existing partnerships with those airlines, though. It might make more sense for WJ to be with skyteam, as alaska is a junior member of oneworld and can be seen as a local competitor.
Westjet has codeshares with American, Cathay, Japan Airlines, Delta and KLM. So fairly tight working relationship with both Oneworld and Skyteam members. I think they are going to do the same thing as Alaska and not join any alliance, they will just partner and codeshare with anyone who is not already a codeshare partner with Air Canada.
Westjet also has interline agreements (permitting baggage transfer and the ability to sell a ticket that involves flights with multiple interline partners) with several more airlines including: Aeromexico, Air China, Air India, Alitalia, British Airways, China Airlines, China Eastern, China Southern, El Al Emirates, Finnair, Korean Air, Pakistan, Air, Qantas, Qatar and SATA Portugal.
The interline agreements are very common. Air Canada has interline agreements with every major airline (and a lot of minor airlines) in the world regardless of alliance. Westjet just started signing interline agreements in the last year or two. Without the interline agreement if you are making a connection between airlines you were forced to buy two separate tickets and the airline was not responsible for making certain you made your connection.