"Control" means the possession, direct or indirect, of the power to direct or cause the direction of the management and policies of a person, whether through the ownership of voting securities, the holding of proxies, by contract other than a commercial contract for goods or nonmanagement services, or otherwise, unless the power is solely the result of an official position with or corporate office held by the person. Control shall be presumed to exist if any person, directly or indirectly, owns, controls, holds with the power to vote, or holds proxies representing, 10% or more of the voting securities or voting power of any other person. This presumption may be rebutted by a showing that control does not exist in fact.
215 ILCS 5/534.8