Delta Air Lines 737-800. By Rob Finlayson

Delta Air Lines (DL) and WestJet (WS) said Tuesday they will expand their cooperation agreement with increased codesharing starting with Jan. 23 flights. 

Calgary-based WS has been following a strategy of network growth via codesharing. It last year inked accords with both American Airlines and DL (ATW Daily News, March 1, 2011). Atlanta-based DL and WS began interlining in 2011, allowing passengers switching between the two carriers to purchase connecting flights on one ticket, receive boarding passes for all segments and check bags through to a final destination.

Under the new codesharing accord, DL will place its code on WS flights to over 15 cities while WS's code will be added to DL flights to five US markets.

"Our codeshare partnership with WestJet means an array of expanded travel options in the US and Canada for our customers, with easy access to the airline's extensive Canadian network and transborder service between Canada and the United States," DL VP-alliances Charlie Pappas said.