The U.S. International Trade Commission has upheld a ruling that Qualcomm Inc. infringed on a Broadcom Corp. patent, the two companies said, dealing a setback to Qualcomm in a wide-ranging legal battle with its rival chipmaker.

The panel affirmed the finding in October by Charles E. Bullock, an administrative law judge, that Qualcomm violated a Broadcom patent to help cell phones conserve battery power when out of cellular network range. The ITC — and the administrative law judge — rejected Broadcom’s claims that Qualcomm violated two other patents.