Delta Air Lines has been asked to submit documents related to its merger with Northwest Airlines, in the US government’s challenge of American Airlines and US Airways’ proposed merger.

Richard Anderson, chief executive of the Atlanta-based carrier, says he was advised that Delta must submit the documents to the court. He made his comments while at the Society of American Business Editors and Writers (SABEW) fall 2013 conference in New York today.

American and US Airways requested the factual records of the US Department of Justice’s (DOJ) review of Delta and Northwest’s merger as well as those of United Airlines and Continental Airlines, and Southwest Airlines and AirTran Airways in 2010, and US Airways and America West Airlines in 2005, on 20 September.

The DOJ called the request “irrelevant” to its challenge of the merger, in a separate filing with the US District Court for the District of Columbia later in September.

District court judge Colleen Kollar-Kotelly did not comment directly on the request during a status hearing on 1 October.

Southwest says that it has not been asked to provide documents.

United did not immediately comment on any requests.

Anderson avoids taking a position on the DOJ challenge of the proposed merger, saying: “Regardless of how that comes out, we’re just focused on running our business and being very successful at Delta.”

He has previously said that consolidation is good for the airline industry and supported the merger, even though it would create a more formidable competitor for Delta.

The American-US Airways case is scheduled to go to trial on 25 November.