Workers went on strike Thursday at Chilean airline LAN, demanding a 15-percent raise and vowing to disrupt flights.
LAN, a subsidiary of Brazil-based LATAM Airlines, showed long delays for certain flights on its website, but said they were caused by bad weather.
The company vowed Wednesday not to let the strike disrupt operations, saying it had contingency plans in place to "minimize the effects."
The LAN Express union, which has some 800 members, said the strike was having an impact.
"There are flights delayed by hours, cancelled flights. The company says it's due to weather, but the truth is it's been overwhelmed by this strike."
Some 40 percent of the company's maintenance and ground personnel for domestic and regional flights joined the strike.
LAN merged with Brazilian airline TAM in 2012 to create LATAM, the largest airline group in Latin America and one of the 10 largest in the world.
LAN operates about 1,500 flights a day in 22 countries.