May 9 (Reuters) - Delta Air Lines ( DAL ) and Korean Air

Lines will acquire an aggregate 25% stake in

Canada's WestJet Airlines for $550 million from private equity

firm Onex Corp ( ONEXF ), the U.S. carrier said on Friday.

Delta will invest $330 million for a 15% stake and Korean

Air will inject $220 million for a 10% interest. The U.S.

airline also plans to sell and transfer a 2.3% stake in WestJet

to its joint venture partner, Air France-KLM, for $50 million.

WestJet, which has had various partnerships with Delta and

Korean Air since 2011, will continue to be owned and controlled

by Onex ( ONEXF ), Delta said.

"Delta, Korean and Air France-KLM are among the world's most

prominent and best-managed airlines. Onex ( ONEXF ) is delighted to

welcome them as shareholders in WestJet," Onex Partners Co-Head

Tawfiq Popatia said.

The agreement comes at a time when Canadian airlines are

seeing a decline in U.S.-bound bookings following President

Donald Trump's tariffs on Canada and suggestions that the

country should be annexed by the U.S.

Air Canada ( ACDVF ), the country's largest airline and a

WestJet rival, lowered its annual adjusted core profit forecast

on Thursday due to the waning trans-border travel, weakening

local currency and trade tensions with the U.S.