Some 1,797 security staff will go on strike from 8pm on Friday, many of them at airports, the union said after wage negotiations broke down.
“People need to allow plenty of time, arriving at least an hour earlier than normal,” Knut Morten Johansen, a spokesman for airline SAS, told news agency NTB.
Johansen added that he did not envisage any flights being cancelled as a result of the strike.
Fears that strike action would paralyze Oslo's Gardermoen airport were alleviated somewhat on Friday afternoon when the Parat trade union said it had accepted a draft solution proposed by wage mediators. Parat had previously indicated that 239 of its members at Gardermoen would go on strike unless a deal could be reached.
But airport operator Avinor suggested that some flights could in fact fall victim to the industrial action.
“The public should expect delays and some cancellations. It’s important that travellers stay informed through their airlines and that they arrive with plenty of time to spare before departure,” said spokesman Ove Narvesen.
The strike is expected to hit passengers hardest in Stavanger, Bergen, Trondheim and Tromsø, while flights from Gardermoen will be less severely affected.