Delta Air Lines (DL, Atlanta Hartsfield Jackson) and WestJet (WS, Calgary) have signed a definitive agreement to form a transborder joint-venture. The carriers have announced that once approved by the authorities, the partnership would entail full codesharing, more closely aligned frequent flyer programmes and benefits, joint growth planning, and co-location at key hubs.

The formal announcement of the joint-venture follows a Memorandum of Understanding inked in December 2017. It is the first such partnership between an American and a Canadian airline.

"Delta's future is global and together with WestJet, we can augment the two airlines' capabilities and bring together our strengths in this important trans-border market," Delta CEO Ed Bastian said.

"WestJet continues its drive toward becoming a global airline, and the signing of this agreement marks a major milestone in that journey," WestJet President and CEO Ed Sims added.

According to the ch-aviation capacity module, in terms of the US-Canada market, the two airlines are nearly the same size. Delta currently offers 49,084 one-way seats per week between the countries, while WestJet offers 48,762 one-way seats per week. This capacity gives the carriers 12.6% and 12.5% market share, respectively. They offer a combined 871 weekly round-trips between the US and Canada.

Once their networks are combined, the Delta-WestJet joint-venture will be the second-largest player on the US-Canada market. The market leader, Air Canada, currently offers 178,028 weekly one-way seats on 1,873 flights.

The two carriers already have an extensive commercial and code-share partnership in place.

Delta currently offers 149 weekly flights to WestJet's hub at Toronto Pearson, 90 to Vancouver International, and 50 to Calgary. Conversely, the Canadian carrier operates 56 weekly flights to Delta's hub at Los Angeles International, 48 to New York La Guardia, 28 to Boston, 21 to San Francisco, and more limited frequencies to other gateways of its American partner.