Delta Air Lines is preparing to open a new Saab 340 base in Atlanta to replace the 12 ATR 72s that are now in the process of exiting the carrier's regional fleet.

Industry sources say that moving some of the 49 Saab 340Bs operated by Northwest Airlines subsidiary Mesaba Airlines to Atlanta is part of the new network and fleet plan that Delta and Northwest are finalising in the lead-up to their merger. The two carriers plan to complete their merger by year-end and will begin shifting aircraft between their hubs next year to exploit network synergies.

Delta seeks turboprops in Atlanta so it can restart its lucrative service to Hilton Head Island in South Carolina, which it is dropping when the last ATR 72 exits its regional fleet at the beginning of December. Hilton Head's runway is too short for regional jets and Delta's withdrawal will leave US Airways subsidiary Piedmont Airlines, which operates Bombardier Dash 8s, as the only carrier serving the popular resort.

Delta is also interested in reintroducing turboprops on several short-haul routes from Atlanta such as Myrtle Beach that Delta is now switching from ATR 72s to regional jets. Jets are not seen as the ideal aircraft on these routes given current oil prices. Sources say a solution seriously being looked at and expected to be implemented is basing several Mesaba 340s at Atlanta. Mesaba now flies out of Northwest's hubs Minneapolis, Detroit and Memphis but the merger opens up new opportunities for it to start feeding Delta.

Sources say Mesaba has indicated all 49 of its Saab 340s, which are leased from the manufacturer, will continue to fly after the merger. But over the long term the merged Delta-Northwest is expected to look at new turboprops. Northwest was evaluating new turboprops, including the ATR 72-600, late last year and early this year but stopped looking after it unveiled plans to merge with Delta.

Sources say Delta was satisfied with the ATR's performance but were keen to close the books on a three-way transaction that was forged when the ATR 72 entered service with Delta's then subsidiary Atlantic Southeast Airlines. Delta sold ASA in 2005 but retained ownership of four of the ATR 72s. The other eight were leased by ASA, but under the terms of the original deal ATR was committed to eventually taking back all 12 aircraft. ATR confirms it has an agreement to take all the aircraft back and says it is now working to remarket them, with several carriers outside North America having expressed interest.

Meanwhile, regional jets are being singled out more than any other aircraft type as Delta and Northwest work on a post-merger fleet plan. Delta earlier this year unveiled plans to remove 70 regional jets from its network, many of which have already been phased out. Managing director of network planning Joe Esposito warns: "It will actually be north of that when we complete our business plan this year".

Northwest has already reduced its McDonnell Douglas DC-9 and Boeing 757 domestic fleets. Delta is also now looking to remarket two 767-300s, which Esposito says will come out of the international fleet in November. But he says there are no plans to sell additional widebodies this year or in 2009 and that Delta plans to continue expanding its international operation.

Source: Flight International