A group of 20 technology companies, car makers and advocacy groups is urging U.S. Federal Trade commissioners to continue the antitrust fight against Qualcomm.

A letter dated Aug. 24 to Commissioners, the Computer & Communications Industry Association (CCIA) and others called for the agency to seek a rehearing before the entire 9th Circuit Court of a recent three-judge panel's finding that Qualcomm's patent licensing practices do not violate anti-monopoly laws.

Some rival chip firms and industry trade groups that supported the FTC's initial antitrust lawsuit against Qualcomm in 2017 signed this latest letter as well, including Intel and ACT/The App Association.

But a handful of auto companies—Tesla, Honda, Ford and Daimler—joined this time in asking commissioners to keep up the battle.

Automakers are increasingly relying on wireless connectivity in vehicles. Today, it's mostly used for onboard infotainment, software updates and roadside assistance.

As faster, more reliable 5G networks become widespread, however, mobile connectivity could become a key technology for powering enhanced safety and self-driving features.

Qualcomm is among the leaders in 5G. The company declined to comment. But executives said recently that the San Diego company has a longstanding 3G/4G patent licensing business with automakers.

On Aug. 11, the three-judge panel of the 9th Circuit threw out a lower court's ruling that Qualcomm's patent licenses were illegal under anti-monopoly law.

A rehearing petition would ask that all the judges of the 9th Circuit weigh in on the case.

FTC commissioners are considering options, according to an agency spokeswoman. They have 45 days from the time when the 9th Circuit panel's findings become official to petition for a rehearing.

If the full 9th Circuit declines, the FTC could ask the U.S. Supreme Court to hear the case.

In the letter, the CCIA and others argued that the panel's decision undermines longstanding U.S. policy and misapplies competition law.

"If it becomes precedent, this decision would endanger domestic competitiveness, as well as weaken the ability of the FTC to protect consumers through future enforcement actions."

Others who signed include MediaTek, HP Inc., Nordic Semiconductor, Denso Corp., the Center for Democracy & Technology, Open Markets Institute and Public Knowledge.