At a hearing at U.S. Bankruptcy Court in Manhattan, Judge Sean Lane held off on confirming the plan for American Airlines' bankrupt parent, but said he found "arguments in favor of confirmation to be fairly persuasive."
"I'd like some time to reflect on them," Lane said.
In a lawsuit filed on Aug. 13, the U.S. Department of Justice sought to block the merger on antitrust grounds, alleging it would create too much consolidation and lead to higher fares for consumers.
At an initial hearing on Aug. 15, Lane voiced hesitation to give his blessing to a plan that might change later, namely through a settlement with the DOJ that could include divestitures.
(Read more: US to block AMR-US Air merger)
Lane ordered the parties to brief him on the best course of action given the DOJ's concerns. The parties filed those briefs last week, and returned to court on Thursday in hopes of getting Lane to budge.
AMR and its creditors' committee argued that Lane's approval of the plan would not conflict with the DOJ lawsuit, which would need to be resolved before the plan could go into effect, regardless of Lane's ruling.
Any divestitures or settlement terms with the DOJ would also require Lane's approval, the parties argued.