"This is very bad news," SAS CEO Anko van der Werff told reporters of the news that will trigger a strike that could paralyse large parts of the embattled carrier's operations.

Close to 1,000 pilots in Denmark, Sweden and Norway will join the strike, according to the unions, which SAS had said could leave some 30,000 passengers stranded each day.

(Reporting by Anna Ringstrom; editing by Niklas Pollard)