Soaring fuel costs and competition have prompted Delta Air Lines to cut more flights at Raleigh-Durham International Airport.

The carrier, based in Atlanta, said Wednesday that it is canceling three daily nonstop round trips to Fort Lauderdale, Fla., on June 5 and has decided not to bring back RDU's only nonstop flight to Los Angeles. A seasonal weekly round trip to Cancun, Mexico, is being discontinued April 16.

Delta spokeswoman Susan Elliott blamed record fuel prices and a change in business strategy toward more profitable international flights for the cancellations.

"During a time when we're dealing with record fuel prices, Delta has opted to streamline its network by reducing marginal routes that will allow us to better use our resources and maintain profitability," Elliott said. "At Raleigh-Durham, that means routing passengers through hubs that offer numerous domestic and international destinations."

Airlines generally make more profit on international flights, which typically have less competition. By August, Delta plans to reduce its domestic schedule 10 percent as it parks as many as 45 planes, Elliott said. But international capacity will climb as much as 15 percent. Elliott could not say whether more cuts are coming in Delta's domestic schedule.

Aviation consultant Mike Boyd said carriers likely will cancel more routes flown by regional jets, which are more costly to operate than larger planes. "They barely made money at $50 a barrel and are hemorrhaging at $100 a barrel," he said.

Other carriers are shedding marginal routes and grounding inefficient planes. Last week, United said it plans to ground 20 older planes, or 4 percent of its fleet. US Airways plans to reduce capacity by 2 percent to 3 percent in addition to initial plans to trim 1.5 percent.

By April 1, ExpressJet will have canceled seven RDU flights to Birmingham, Ala.; Jacksonville, Fla.; and Louisville, Ky., less than a year after they began. Delta Connection ended a once daily round trip to Tampa from RDU on Jan. 31.

Delta, with 33 daily flights, is the third-busiest carrier at RDU, behind American and American Eagle and Southwest Airlines.

RDU officials had hoped Delta would restart the Los Angeles flight, which business leaders had lobbied to get. The flight suffered because of a late-night return leg that many passengers disliked. Delta ended the flight Jan. 7, just 18 months after it began. After lobbying by RDU, Delta said it would consider making the flight a seasonal service during the summer, but it has scrapped those plans.

Competition from low-fare carriers JetBlue and Southwest apparently helped ground Delta's Fort Lauderdale service. The three daily Delta flights offered a total of 300 seats to South Florida and back.

But the total number of available seats between the markets more than doubled after JetBlue began a once-daily flight with a 100-seat jetliner in January and Southwest added a daily round trip with a 137-seat jetliner in February, adding a total of 474 seats.

Travel in Style agency co-owner Darlene Stull said Delta's Fort Lauderdale flights regularly had been full of leisure passengers heading for cruise ships. Now it's JetBlue and Southwest flights scheduled for the summer that are being filled, she said.

"Delta opted not to compete," said Stull, whose agency is in Raleigh.