You can definitely purchase a bankrupt airline's trade symbol. Pan Am's blue globe was purchased from the estate of Pan Am for around $1.2 million dollars by what became Pan Am 2.
I don't believe that Cintra (AeroMexico's parent company) has anything to do with the brand anymore. If you remember correctly, AeroPeru came very close to being relaunched by a private group along with the ex-employees of AeroPeru. However, the plans fell through. They even went all the way to leasing a 737 for several months that never took off. So this group is now the owner of AeroPeru's name and logo.
TANS Peru, the government owned airline of Peru, was also interested in purchasing the rights to Faucett's name brand. Faucett was one of the oldest airlines in the region that suffered the same fate like AeroPeru. The plans to acquire the name also fell through. Would have been nice though.
Pan Am - The World's Most Experienced Airline.