Volaris (Y4, México City International) and Aeroméxico (AM, México City International) were found "probably liable" by the Mexican antitrust authority (Comisión Federal de Competencia Económica - COFECE) for anti-competitive practices on domestic routes between April 2008 and February 2010 and face fines of up to 10% of their revenues from the years in question.

The ruling is preliminary and subject to further proceedings. COFECE's investigation may also involve other carriers, however, only the publicly traded Volaris and AeroMéxico have announced that they face fines. Other airlines active on the Mexican domestic market in 2010 include Interjet and VivaAerobus.

Volaris said the maximum fine it faces amounts to USD4.6 million and "is not expected to have a material adverse effect on the performance of the company".

AeroMéxico did not disclose its potential liability. According to the carrier's financial reports, it recorded MXN28.08 billion (USD1.5 billion) revenues in 2010 and MXN22.35 billion the year before.

Both carriers underline they fully cooperate with COFECE and stated that the current findings are only preliminary and may be reversed.