American Airlines formally denied interest or engagement in merger discussions with United Airlines late Friday. The announcement followed reports that United’s CEO discussed a potential acquisition with senior administration officials earlier in the week.

American Airlines stated a combination would harm competition and consumers. The carrier noted a merger conflicts with current antitrust laws and the administration’s industry philosophy.

American Airlines shares fell 1.4% in extended trading following the announcement. This decline reversed a steady rise in stock price driven by merger speculation throughout the week.