US regional Comair could see as many as 77 more Bombardier regional jets, including its entire CRJ700 fleet, culled from its feeder deal with parent Delta Air Lines should its bid to secure a portion of its current flying fail.

Delta forced its regional partners to re-tender for existing services earlier this week, when it issued a request for proposal (RFP) for the operation of 143 regional jets. This RFP includes up to 43 70-seaters and up to 50 50-seat regional jets already operated by Delta Connection carriers Comair, Mesa Air Group’s Freedom Airlines unit, and Republic Airways’ Chautauqua Airlines and Shuttle America subsidiaries.

The RFP represents a portion of the Delta Connection network that has not been affirmed in the bankrupt major’s Chapter 11 proceedings.

Delta is also soliciting bids for the operation of up to 50 76-seat aircraft that the carrier can add to the Connection fleet “to meet the changing demands of the network”.

Comair confirms that its 27 owned Bombardier CRJ700s - representing its entire fleet of 70-seaters - are included in Delta’s RFP. The regional also says that at least some and as many as 50 of its 50-seat regional jet fleet could also be affected.

This is in addition to the 30 50-seat regional jets in the process of being cut as part of a prior move by Delta in bankruptcy.

At the end of last month, Comair operated a total of 168 regional jets on behalf of Delta, according to Delta.

“Today’s RFP is the latest - and perhaps most clear - demonstration of the risk or opportunity Comair faces as we continue to encounter delays in our restructuring,” says Comair president Don Bornhorst.

He adds: “We have repeatedly urged the completion of this process and working together is the only way for us to pursue a brighter future.”

To this end, Comair says it intends to bid on the RFP to both retain its current flying levels, and add 76-seat operations. “The responses are due back by September 18 and then Delta has said it will award that flying prior to emerging from bankruptcy in early 2007,” says the spokeswoman.

Should its bid fail, Comair could face the loss of 77 regional jets under a worst case scenario.

Comair will meet with the carrier’s flight attendants union this week in Washington, DC. Management will also return to negotiations with the pilots and mechanics unions later in the month.

Mesa and Republic Airways, meanwhile, must also bid to retain the portions of their flying affected by Delta’s RFP.

Mesa’s Freedom subsidiary is currently contracted to fly 30 50-seaters for Delta, while Indianapolis, Indiana-based Republic’s regional subsidiaries, Chautauqua and Shuttle America, operate as Delta Connection with Embraer ERJ-145 and E-170 aircraft, respectively.

As of December 31, a total of 48 of Republic’s 142 regional jets were flown on behalf of Delta.

Mesa and Republic could not be immediately reached for comment.

Delta says the RFP does not jeopardise other regional jet operations currently contracted by the bankrupt US major.