The Seattle Art Museum will return a painting by Matisse to the heirs of a French Jewish art dealer from whom it was confiscated by the Nazis in 1941.The museum's board of trustees voted unanimously to return the painting, ''Odalisque,'' on Monday afternoon, less than a year after descendants of the prominent dealer Paul Rosenberg filed suit in Federal District Court in Seattle to recover the work. The lawsuit was the first against an American museum concerning ownership of art looted by Nazis during World War II.(English)