SAN FRANCISCO — The fee-shifting walls keep closing in on famed Chicago patent litigation firm Niro Haller & Niro.

A Chicago federal judge has ruled that a Niro Haller client’s inequitable conduct before the U.S. Patent and Trademark Office made the company’s subsequent litigation with Dell Inc., Sharp Corp., Palm Inc. and Hewlett-Packard Co. an “exceptional case” worthy of a fee award under Section 285 of the Patent Act.