A Norwegian museum has agreed to return a Matisse painting, looted by the Nazis, to the family of Jewish art dealer Paul Rosenberg.
Woman in a Blue Dress in front of a Fireplace has been on display at the Henie Onstad Art Centre (HOK) since 1968.
The gallery said that although it acquired the painting in good faith, it had "chosen to adhere to international conventions and return the painting.''
Its worth is estimated at $20m (£12m).
The work was painted in 1937 and bought by Rosenberg, the famed art collector who represented Picasso as well as Matisse.
Rosenberg was forced to leave his collection behind when he fled France in 1940 to escape Nazi persecution.
The painting was one of 162 works taken from his collection in 1941 by the special Nazi looting agency known as the Einsatzstab Reichsleiter Rosenberg (ERR).
It was later acquired by Gustav Rochlitz, an art dealer who was convicted in France in 1947 for dealing in Nazi looted art.
In 1950, a gallery in Paris that was unaware of its provenance, sold the painting to shipping magnate Niels Onstad.
Onstad and his wife, Olympic figure-skating champion Sonja Henie, founded their art centre near Oslo in 1968 with the painting as one of its highlights.
The heirs of Paul Rosenberg contacted the Henie Onstad Art Centre in 2012 and presented documentation demonstrating it was unlawfully taken.
Extensive research was conducted by the art centre and the Rosenberg heirs in French and American archives, which confirmed the painting was stolen from Rosenberg as a result of Nazi persecution.
Tone Hansen, HOK's director called the painting a "key work" for the gallery.
"The comprehensive investigations have been exhaustive and HOK has taken the time necessary to examine all available facts in the case.
"Our knowledge of archives and resources regarding provenance research will be made available to the public through a variety of exhibitions, seminars and publications during 2015."
The case is the first of its kind in Norway.
According to the Jewish Claims Conference, the Nazis seized an estimated 650,000 artworks and religious items from Jews and other victims.
In 2013, a cache of 1,500 looted artworks found in Munich was called "the tip of the iceberg" as many owners are still trying to recover their property.