Avianca Holdings SA, Colombia’s largest airline, said it won’t continue its integration plan with low-cost carrier Viva Air on concern regulations from the nation’s civil aviation authority could affect its stability.

The regulations required Avianca to assume commitments, air routes and prices that didn’t correspond to Viva’s real capacities after it suspended operations for two months, Avianca said in a statement Saturday. 

“Unfortunately, this long process puts Viva, the airline that brought the low-cost model to the country, at imminent risk of disappearing,” Avianca Chief Executive Officer Adrian Neuhauser said in the statement. 

The civil aviation authority said in March it had approved the integration between the airlines with conditions, including maintaining its low-cost plan.

Viva Air said later in a statement that without financial backing “the company does not have the capacity to continue operating.”