Still at odds over a long-term reauthorization of the Federal Aviation Administration, senators have begun drafting another temporary extension for the agency, which faces a budget crunch in less than two legislative weeks.

Aides and lobbyists said congressional staffs have circulated competing bills: one to extend FAA programs through June and the other through the end of September.

According to a letter the FAA sent to lawmakers Jan. 29, the agency will have to start laying off some 4,000 employees March 1 if Congress does not extend the agency's authority to collect and expend the tax money that fuels much of its budget.

John D. Rockefeller IV, D-W.Va., confirmed Thursday that staff members are preparing a short-term extension. The current extension (PL 110-161) expires Feb. 29.

Rockfeller said he seeks an extension through the end of fiscal 2008, in September. Finance Chairman Max Baucus, D-Mont., prefers a shorter time frame.

"That in itself doesn't provide a whole lot of comfort, but it's probably all that we can do in this particular year," Rockefeller said of his proposal, adding that it is unlikely that Congress will finish a four-year bill this year.