ATLANTA ( TheStreet) -- Delta ( DAL) may push ahead of Southwest ( LUV) to become the first U.S. carrier to code share with WestJet. Calgary-based WestJet, a low-fare carrier built on the Southwest model, flies Boeing 737 jets to 69 cities in North American and the Caribbean. On its Web site, it says its goal is "to be one of the five most successful international airlines in the world." In this regard, a code-share agreement with a U.S. carrier would be beneficial. In July 2008, Southwest and WestJet said they had reached an initial agreement on a code-share deal that would create a cross-border low-fare partnership. But now CEO Gregg Saretsky said WestJet may code share first with Delta. Delta "has an interest," Saretsky said recently, in an interview with the Financial Post. "They have a capability. We like the Southwest partnership, but they've signaled to us that they're not going to be ready." Before joining WestJet in June 2009, Saretsky worked at Alaska Airlines ( ALK), where he led the development of an alliance strategy that included forming an alliance with Delta in 2008. More recently, Delta and US Airways ( LCC) offered WestJet slots at New York's LaGuardia airport, as the devised slot exchange deal that would offer slots to four of North America's leading low-cost carriers. They excluded Southwest, the largest low-fare carrier. Since acquiring Northwest to become the world's biggest airline, Delta has not rested on its laurels -- if anything, it has become more competitive. In Asia, it sought to replace American ( AMR) as partner to Japan Air Lines. Now, it is apparently seeking to elbow ahead of Southwest in Canada. -- Written by Ted Reed in Charlotte, N.C. .