By Jonathan Stempel

(Reuters) - A divided federal appeals court on Friday ruled against Indivior Plc in its bid to stop Dr. Reddy's Laboratories Ltd and Alvogen from selling generic versions of its opioid addiction treatment Suboxone film that infringed its patents.

The U.S. Federal Circuit Court of Appeals in Washington, which oversees many intellectual property cases, upheld lower court rulings that Dr. Reddy's did not infringe two Indivior patents related to Suboxone, and Alvogen did not infringe one of those patents.

Suboxone film is applied below a patient's tongue, where it dissolves to release two active ingredients, buprenorphine and naloxone.

It had accounted for about 80 percent of Indivior's revenue, but the London-based company forecast declines after the U.S. Supreme Court in February allowed sales of generic equivalents, including by India-based Dr. Reddy's.

Circuit Judge Alan Lourie wrote for a 2-1 majority that while Indivior's patents should not be voided, it failed to show that they covered Dr. Reddy's and Alvogen's drying processes for their products, or a polymer that Dr. Reddy's used.

The court also said another generic drugmaker, Teva Pharmaceutical Industries Ltd, did not show that the patent concerning the drying process should be voided.

Indivior launched the first buprenorphine-based product to treat opioid dependence in 1996. It had sought damages, as well as injunctions against the U.S. sale of infringing products, in lawsuits underlying Friday's decision.

The dissent said Indivior's patents should have been voided because they described methods to produce sublingual films that were already known, and were therefore "obvious."

Indivior's lawyers did not immediately respond to requests for comment.

Kevin Martin, a lawyer for Dr. Reddy's, said in an email: "We're glad that the Federal Circuit has again concluded that Dr. Reddy's generic films are non-infringing, which will keep this low-cost treatment option on the market."

Alvogen spokesman Halldor Kristmannsson said the company, which has offices in New Jersey, was also pleased. Teva's lawyers did not immediately respond to requests for comment.

Indivior was separately indicted in April by a federal grand jury in Virginia for allegedly scheming to boost Suboxone film sales. The U.S. government wants Indivior to forfeit at least $3 billion.

On Thursday, Reckitt Benckiser Group Plc, which spun off Indivior in 2014, agreed with U.S. regulators to pay up to $1.4 billion to settle similar claims. Indivior said that settlement was separate from its own case.