A former partner at Omaha, Neb.-based Kutak Rock has sued the firm, alleging that its decision to keep a portion of his capital account by imposing a clawback provision contained in the firm’s partnership agreement amounts to an anti-competitive effort to punish him for joining another firm.

Paul Donsbach, who was based in Kutak Rock’s Los Angeles office, filed his lawsuit last week in Los Angeles Superior Court. In the complaint, Donsbach asks the court to void the partnership agreement provision (pdf) that would force him to arbitrate his dispute with the firm in Nebraska and to order Kutak Rock to return a $30,000 penalty the firm seeks to impose on him.