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.
"In many ways, this is an historic agreement bringing two Norwegian airlines together. A lot of detail is still being worked on but it’s clear from the past months’ discussions with Wideroe that there are many areas we both have a common interest to collaborate on."
