Delta Air Lines and Korean Air will buy a combined 25 per cent stake in WestJet from Canadian investment firm Onex, the companies announced on Friday.

U.S.-based Delta Air Lines (DAL) and Korean Air Lines are buying a combined 25% stake in Canada’s WestJet Airlines for $550 million U.S. The deal will see Delta invest $330 million U.S. for a 15% stake in WestJet and Korean Air invest $220 million

The investment comes at a shaky moment for travel between Canada and the U.S., with Canadians taking fewer trips to the U.S.