The wave of fare sales sweeping the airline industry reached Salt Lake City on Wednesday when Delta Air Lines announced a coast-to-coast sale in nearly 300 cities across the U.S. and Canada.

Until Delta announced its sale, the carrier was only matching cheaper fares on routes out of its Salt Lake City airport hub where it has competition, said Rick Seaney, head of airfare research site FareCompare.com.

"They were basically matching. No airline in this [tight business environment] is going to allow somebody to undercut their prices," Seaney said.

Delta is the dominant airline at the Salt Lake City International Airport. Together with its Northwest Airlines subsidiary and its Delta Connection partners, the carrier controls more than 70 percent of the passenger market.

Seaney said airlines typically announce fare sales in January, but the bargains this year are different. Worried about the economy, the airlines are offing discounts for flying as late as June, he said.

"In past years, sales were for travel through the end of February or early March and didn't include Spring Break, but these are basically going to the end of May and June. They are trying to pre-book because there is so much uncertainty over the economy in the next four or five months," he said.

Many experts and even executives at some airlines had expected that after deep seat capacity cuts went into effect in September, the number of fare sales going forward would be fewer and farther between. But fuel prices have come down significantly, and the weak economy has eroded demand for air travel. Even so, on average base airfares are higher today than in the last few years, Seaney said. There were 30 attempted airfare increases from summer 2007 to last summer, and most were successful, he said.

Delta and Northwest join American Airlines, JetBlue Airways, Southwest Airlines and United Airlines, which have launched fare sales since Dec. 31. The sales do not affect fees for baggage or other services, which remain in place.

Delta said its sale prices are available through April 30, though rates for travel beyond March 4 could be higher. Tickets must be purchased at Delta.com at least 14 days prior to departure, but no later than Jan. 16.

Nonstop fares range from $94 one way to $184. Flights from Salt Lake City to O'Hare International Airport in Chicago are $94, matching American's fare between the two cities. A one-way ticket to Boston is $179.

Tickets cost $20 more if bought over the phone and $35 more if purchased at a Delta counter.

New York-based JetBlue Airways said Monday it was offering a fare sale involving more than 40 destinations in the Northeast, Florida, California and the Caribbean, including a $109 one-way fare from Salt Lake City to New York's John F. Kennedy International Airport and $39 to Las Vegas. For most city pairs, travel must take place between Monday and April 1.

Other carriers that have kicked off fare sales include Southwest, for travel between Jan. 15 and April 30; American, for travel within the U.S. between Jan. 14 and March 4, and between March 5 and April 30 at slightly higher fares; and United, for travel within the U.S. from Jan. 14 to March 4 and for travel to several foreign destinations as late as April 30.

"Obviously, less demand has had some effect on fare sales," American spokesman Tim Smith said.

The Associated Press contributed to this story