Will they or won't they?

Delta Air Lines said Friday that it is discussing an alliance with United Airlines, but United later said the talks have been suspended.Atlanta-based Delta is the nation's third largest carrier and Utah's dominant airline, operating a hub and spoke system out of Salt Lake International Airport. United, based in Chicago, is the nation's largest carrier.

Delta termed the discussions "extensive" and concern a "possible global strategic alliance, including code-sharing and other cooperative commercial activity, which would respond positively to the demands of travelers."

But in a statement issued shortly after Delta's, United said the talks have been suspended "and may or may not be resumed in the future." Until an agreement is reached, United said it will make no further comment on the alliance.

Whether it eventually goes through or not, the deal would be limited to a marketing alliance and would not include a corporate merger or other equity investment.

The talks between Delta and United came in the wake of a variety of alliances among the nation's largest carriers who are in various stages of sharing everything from frequent-flier programs to flight schedules.

American Airlines and US Airways are currently forming an agreement and Northwest Airlines has already said it will buy a $519 million stake in Continental Airlines that would link their route systems.

American also has deals pending with British Airways.

The Times said that if and when the latest alliances become effective, the carriers involved will be able to market and sell tickets on their partners' flights, a practice known as code-sharing.

Frequent flier programs will also be linked, giving members more destinations to choose from, and passengers will also be given access to each others' airport clubs.

"But it doesn't mean lower fares," said Samuel Buttrick, the airline analyst for Paine Webber.

"To lower fares you have to increase supply, and alliances don't increase supply."