The committee, a key player in Delta's Chapter 11 case, said it reached its decision after a lengthy review of both airlines' proposals.
US Airways of Tempe, Ariz., had asked for the committee's support of its two-month-old takeover run by Thursday.
"We are disappointed that the committee, which has been chosen to act on behalf of all Delta creditors, is ignoring its fiduciary obligation to those creditors," US Airways Chairman and Chief Executive Officer Doug Parker said.
"It is now clear that there will not be an opportunity with the committee to move forward in a timely or productive manner and, as a result, we have withdrawn our offer."
US Airways' withdrawal clears the way for Delta management to continue its plan to emerge from bankruptcy this spring as an independent airline.
A court hearing on Delta's reorganization plan set for next Wednesday could let Delta seek creditors' votes for its plan.
Delta, based in Atlanta, has projected it will be worth $9.4 billion to $12 billion when it emerges from bankruptcy.