Patent work done by Pennie & Edmonds for an herbal supplement-maker in 1997 does not bar the New York firm from representing a third party suing its former client over the supplement’s name, a federal judge has ruled.

Southern District Chief Judge Thomas P. Griesa declined a motion to disqualify the 150-lawyer firm after noting substantial differences in the previous and current work and a “screen” erected between the trademark and patent lawyers handling it.