Airline and aviation workers at Aerolíneas Argentinas and Austral walked off the job at Buenos Aires’ major airports on Thursday, affecting over 7,000 passengers.
Fifty-seven flights at the Ezeiza International airport and the downtown Aeroparque airport were either delayed or cancelled.
The disruptions to flights could continue if unions decide to prolong assemblies, which began late last week, aimed at discussing the prospect of broader strike activity over layoffs and salary stagnation in the sector.
"It's a disguised and shock strike action because they (unions) have not specified any demands (for the company) to address", Aerolíneas Argentinas spokesman Marcelo Cantón told the Todos Noticias news channel.
"There is no demand. They are holding assemblies in which employees of the company make arguments but there has been no formal presentation", he added.
"The company is open to dialogue. The wage bargaining talks expired on September 30. In this case, there is not demand of presentation for us to attend to", Cantón said.
On Friday, flights from Aeroparque airport in Buenos Aires were delayed because of assemblies involving staff at the smaller nationally-owned carriers FlyBondi and Andes.
Inflation in Argentina is expected to surpass 40 percent in 2018, prompting concern among unions across all sectors about real wage loss.
Argentina's commercial travel sector also is experiencing a shake-up with the growth of low-cost tourism.
Over 630 new routes were granted to 13 companies in tender processes during 2017. FlyBondi and Norwegian Air are two of the newcomers which are already operating in the country.
Unions say low-cost travel will impact conditions and safety standards for workers and passengers.