Southwest Airlines is trying to solidify deals to book international travel to Mexico and Canada.
Southwest has planned for more than a year to operate U.S.-Canada flights in a partnership with Canada's WestJet, which would actually do the cross-border flying. But Canadian media reports indicate WestJet is talking about hooking up with Delta instead.
Southwest said Thursday a WestJet-Delta deal might make the Southwest-WestJet partnership impossible.
If it can't work out its differences with WestJet, Southwest said, it will look for other ways to offer customers flights to Canada.
Dallas-based Southwest carries more U.S. passengers than any other airline, but it doesn't fly to other countries. In July 2008, CEO Gary Kelly announced that in "a big step," the carrier would add service to Canada through a deal with WestJet.
Since then, Southwest announced plans to cooperate with Volaris on service to Mexico. It also would like someday to sell travel to the Caribbean and Europe.
Under a so-called code-sharing agreement, Southwest would sell seats on WestJet planes flying from a few locations in the United States to Canada. The two airlines would share the revenue.
The airlines initially planned to announce schedules and other details by the end of 2009. Gregg Saretsky, who became WestJet's CEO on Thursday, has said Southwest wasn't ready.
In a statement Thursday, Southwest's executive vice president of planning, Bob Jordan, disputed Saretsky's claim. He said the venture was going according to schedule, but he added that WestJet tried to change the agreement in ways Southwest couldn't accept.
"We are, and always have been, prepared to move forward to implement our agreement with WestJet," Jordan said. If WestJet walks away to make a deal with Delta, he added, Southwest is still very interested in selling travel to Canada.
WestJet started as a regional carrier in western Canada and has grown into a low-fare rival to Air Canada. Like Southwest, it uses Boeing 737 jets.