If the deals are finalized, MacLaine and Caine will play the parents of Samantha, the role in which Nicole Kidman has already been cast, Empire Magazine Online reported Monday.
Nora Ephron will produce the film about the mishaps that occur when Samantha, a witch, marries Darrin, a human. Will Ferrell will play Darrin in the updated script.
MacLaine has been favored from the beginning of the project for the role of Endora, originally was played by Agnes Morehead, because of her red hair and impish on-screen antics, Empire said.
MacLaine and Caine have appeared on screen together only once before, in 1966 in "Gambit."
MacLaine currently is filming "In Her Shoes" with Cameron Diaz and will then move on to "Closing the Ring." Michael Caine is filming "The Weather Man" with Nicholas Cage and is playing Alfred in "Batman Begins."