This means, among other initiatives, the two companies will cooperate on tickets sales, enabling passengers to travel the entire route network of both airlines under a interline agreement.
The objectives of the agreement will "provide a better service to passengers" and create "synergies and operational efficiencies".
Norwegian’s chief executive, Geir Karlsen, said: "I am very pleased with the agreement we have entered into with Wideroe today. Our goal for this collaboration is to benefit both companies’ passengers and our employees.