The other side of midnight (1977)

When French beauty Noelle Page falls in love with American pilot Larry Douglas, she believes he'll marry her. Instead, he returns to the U.S and marries the sweet but naive Catherine. Even though Noelle has found a new lover, an affluent Greek named Constantin, and has started a great career as an actress, she vows revenge on her onetime lover. But once her plan is in motion, she and Larry fall in love and plot Catherine's death.