DALLAS (AP) A code-sharing program involving Southwest and the Canadian airline WestJet has been delayed because of difficult economic conditions.

"In response to the current economic environment, Southwest is focusing its immediate attention on several critical objectives, including increasing our revenues," Bob Jordan, Southwest Airline's executive vice president, strategy and planning, said in a news release Monday.

Jordan said the Dallas-based airline remains committed to partnership with WestJet and to code-sharing.

Code-sharing involves selling seats on each other's planes and sharing the revenues with one airline putting its name or code on a flight operated by the other.

"WestJet understands the decision made by Southwest. Our continued U.S. expansion is a key strategy for our airline, but code-sharing is only one element of this. Both airlines remain committed to minimizing delays and are focused on generating revenue as quickly as possible," said Hugh Dunleavy, WestJet's executive vice president, commercial distribution.

Dunleavy said WestJet has already implemented a distribution agreement and is close to starting a cargo program with Southwest.

Code-sharing is considered a low-risk way for airlines to expand their networks without the added cost of more planes and employees. It figures to be a particularly important strategy for Southwest, which is alone among the nation's major carriers in not belonging to one of three big global alliances or teams of airlines.

Copyright 2009 The Associated Press.