The agreement between Southwest Airlines Co. and the WestJet Airlines Ltd. was cancelled by the former on Friday. This two-year old code sharing agreement was put to an end after low-cost Canadian carrier tried to overhaul the terms of the original deal.

It has been known that WestJet wanted to alter the long-delayed, union to opt for an alliance with Delta Air Lines Inc. Southwest stated that after revising the number of changes that WestJet has appealed, it decided that it would be good for both the parties to work independently.

This pact was signed by the two parties back in July 2008; it has not been implemented as of now.

It was alarmed by Southwest on April 1 that if WestJet opted for the potential codeshare with Delta, it "could be inconsistent" with the deal and would not be in tune with the requirement with its current agreement.

The codeshare pact was scheduled to initiate in late 2009, but it was extended till late 2010. Earlier, WestJet said that the delay was due to some technological issues in Southwest.

Also, according to a statement that came from WestJet, the decision of terminating the agreement is “best for both companies". WestJet did not elaborate any information regarding the Delta deal.