Finding Kobre & Kim’s efforts to isolate a newly hired partner from a potential conflict inadequate, a state judge has disqualified the firm from representing a client in an arbitration against former employees of Lehman Brothers Holdings Inc.

Manhattan Supreme Court Justice James Yates (See Profile) granted a motion Thursday in Chernick v. Essex Equity Holdings USA, LLC, 600995/2010, by the former Lehman employees to disqualify Kobre & Kim from representing Essex Equity Holdings USA LLC, which is pursuing a $285 million arbitration claim over the sale of auction rate securities by the bank’s brokerage arm.