The ASPA pilots union filed a lawsuit against Grupo Posadas, the former owner of bankrupt Mexicana de Aviacion, alleging violations of securities laws in the airline's management.

Grupo Posadas chairman Gaston Azcarraga "hid important results and indicators of liquidity, solvency, profitability and utilization of assets" while the company ran Mexicana de Aviacion, actions that "may have exacerbated the company's crisis," ASPA chief Fernando Perfecto, whose union represents more than 2,500 pilots in Mexico, said.

Mexicana was acquired from the government by Grupo Posadas, a hotel operator, in late 2005.

The carrier, which ceased operating last August due to severe financial problems, is in the hands of a court-appointed receiver, who will decide whether the company can resume flying or will be liquidated.

Grupo Posadas failed to report that it took out two large loans, one for 1.5 million pesos ($127,000) from Grupo Banorte and another for 991 million pesos ($83 million) from Banco de Comercio Exterior, Perfecto said.

The company also failed to report other "material" information about Grupo Mexicana de Aviacion, the union leader said.

Mexicana, which had been one of Mexico's two leading airlines, stopped operating on Aug. 28 along with sister budget carriers Click and Link.

Several investor groups, including Avanza Capital, Ivan Barona, Altus Prot and TG Group, have expressed an interest in the carrier, but no one has been able to seal a viable deal.

On Sept. 7, a Mexican judge allowed the airline to suspend payment on its debt and left it in the hands of a court-appointed receiver.

The carrier is trying to negotiate a restructuring of its debt of about 20 billion pesos ($1.67 billion), of which a large portion is owed to workers.

In March, Mexicana's sale was cancelled after buyer PC Capital was unable to come up with the funds needed to buy the carrier and subsidiaries Click and Link.

PC Capital failed to pay the money on March 1, the day that the purchase agreement expired, Tenedora K, which took control last August of 95 percent of the stock of holding company Nuevo Grupo Aeronautico, or NGA, which owns Mexicana de Aviacion, Click and Link, said.

PC Capital won the bidding for the bankrupt carrier in November, offering to pay $200 million for Mexicana's assets and to restructure operations.

Mexicana de Aviacion, which had planned to resume flying before March, had received its operating and security licenses after conducting test flights mandated by regulators.

Earlier this month, about 2,500 Mexicana employees filed a complaint with prosecutors against Banco Nacional de Comercio Exterior, or Bancomext, alleging that the state-owned financial institution defrauded the Treasury of some 990 million pesos (about $83 million) and dispossessed the company of assets.

The government said earlier this month that it was not going to bail out Mexicana.

There is no "possibility whatsoever" that the government will take over the airline, Labor Secretary Javier Lozano said on June 1.

The carrier could be liquidated if no deals to help it resume flying are finalized before Aug. 5.