A general strike in Spain set for 29 September will see international travel affected with unions agreeing to provide a minimum of between 20% and 40% of flights.
The protest against austerity cuts and labour reform will leave at least 20% of European flights and 40% of other international flights unaffected, the reports said.
At least one quarter of train services would run, according to the deal reached, rising to 30% at rush hour.
Neither the Development Ministry nor trade union organisations could be reached for comment.
Under Spanish law, workers in certain sectors must provide a minimum level of services and the unions must agree with the government on what minimum levels should be.
The scale of transport stoppages is likely to be a key factor in the level of disruption caused by the strike as they determine how many non-strikers can get to their place of work.
A poll for El Pais by Metroscopia on 5 September showed that although 58% of Spaniards thought the strike was justified, only 9% said they definitely planned to take part.
However, some analysts thought participation on the day was likely to be higher and there would be significant disruption in large cities.
