Siding against broadband providers, the 9th Circuit Court of Appeals on Wednesday refused to reconsider whether California can enforce its net-neutrality law.
The move leaves in place a decision issued in January, when a three-judge panel of the 9th Circuit upheld the California measure.
That law, passed in 2018, prohibits broadband providers from blocking or throttling traffic, charging higher fees for fast-lane service, and exempting their own video streams from consumers' data caps.
The Federal Communications Commission passed similar regulations in 2015, but repealed them during the Trump administration.
Four industry groups (American Cable Association, CTIA -- The Wireless Association, NCTA -- The Internet & Television Association and USTelecom -- The Broadband Association) challenged the law and sought an injunction against its enforcement.
They argued that internet access is "inherently interstate," and should not be subject to state laws. The organizations also said California's law conflicted with the FCC's decision to repeal the 2015 rules.
U.S. District Court Judge John Mendez in Sacramento rejected the broadband industry's arguments and refused to block the law from taking effect.
The providers then appealed to the 9th Circuit, which upheld the law. Circuit Justice Mary Schroeder wrote that the FCC's revocation of the Obama-era rules did not prevent states from passing their own laws.
The industry groups then asked the 9th Circuit to reconsider that ruling, arguing that it will result in a "patchwork of conflicting laws" that "will harm broadband deployment and cause customer confusion."
"Whether broadband Internet access service ... will continue to be subject to a uniform, nationwide regulatory regime is a question of exceptional importance," broadband industry groups argued in a request for a new hearing.
It's not yet clear whether the broadband industry will attempt to appeal to the Supreme Court.
Former agency head Ajit Pai, who shepherded the repeal of the Obama-era rules, called them "heavy handed" and claimed they depressed investment.
But net-neutrality proponents say rules are necessary to prevent broadband providers from limiting consumers' ability to access streaming video, search engines and other online services and content.