(Reuters) - A U.S. appeals court on Friday turned away a challenge from Apple, Google, Intel, Cisco Systems, and Edwards Lifesciences to a U.S. Patent and Trademark Office action that reduced the number of patent-validity reviews at the agency.

The U.S. Court of Appeals for the Federal Circuit rejected the companies' request to block an internal rule that gave the agency's judges greater discretion to deny "inter partes review" petitions, which are often used by big tech companies to invalidate patents they are accused of infringing.

Spokespeople for the USPTO, Intel and Cisco declined to comment on the decision. Spokespeople for the other companies did not immediately respond to requests for comment.

The inter partes review process at the USPTO's Patent Trial and Appeal Board is popular with companies that are frequently targeted with patent lawsuits. An internal rule that gave the agency's judges greater discretion to deny review petitions "dramatically reduced access" to the process, the companies told the appeals court.

The companies sued the PTO in the California federal court in 2020 over the rule, arguing it violated federal law and undermined the role the inter partes review plays in "protecting a strong patent system."

The California court dismissed the case in 2021, citing U.S. Supreme Court rulings that Patent Trial and Appeal Board decisions on whether to review inter partes review petitions cannot be appealed.

The Federal Circuit revived the companies' lawsuit in 2023. The appeals court had found then that the agency may have failed to go through a required public notice-and-comment process before making the rule.

The California court rejected the companies' challenge again in 2024. A three-judge Federal Circuit panel on Friday affirmed the court's ruling that notice and comment were not necessary because the internal rule was only a "general statement of policy."

The case is Apple Inc. v. Squires, U.S. Court of Appeals for the Federal Circuit, No. 24-1864.