Baldwin, who appeared in "The Usual Suspects," is suing Costner, star and director of "Dances with Wolves," for unspecified damages, TMZ said Thursday.
Baldwin said he was a 10 percent partner in a Costner-backed company that makes machines that separate oil from water. In court papers, he said Costner and his partners "schemed" to get him to sell his shares back to the company so they could gain a larger part of the profits in the wake of the BP oil disaster, the entertainment news Web site said.
Costner's representatives did not respond to a request for comment, TMZ said.
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