The Federal Trade Commission said Monday it had settled litigation that Endo International violated antitrust laws when it entered "anticompetitive reverse-payment" deals with rivals Watson Laboratories and Impax Laboratories to block lower-cost generic versions of Endo's pain medicines.

The FTC charges were originally filed in U.S. District Court in Philadelphia in March 2016, alleging that Endo used "pay for delay" agreements with Watson, now part of Allergan, and Impax to stay off the market with cheaper generic versions of Endo's Opana ER, an opioid painkiller, and Lidoderm, a topical lidocaine patch, the FTC said.

Endo, with U.S. headquarters in Malvern, said Monday that it entered into a 10-year stipulated order with the FTC. Under the order, Endo will make no monetary payment, and the FTC will dismiss claims against the company. Endo will also not admit wrongdoing, the company said.

In the proposed settlement, the FTC sought an order barring the defendants from engaging in "similar anticompetitive behavior" in the future.

In the original lawsuit, the FTC alleged that "Endo knew that generic competition would decimate its sales of the corresponding branded product, and that any delay in generic competition would be highly profitable," the agency said. "Faced with these threats to its lucrative drug franchises, Endo bought off its potential generic competitors." Sales of Opana ER and Lidoderm were close to $1 billion in 2009, when the drugs were still on patent.

"Endo is extremely pleased with the FTC settlement," said Endo chief legal officer Matthew J. Maletta.

Endo shares have fallen from $18 a share on Jan. 2 to  $12.17 Monday. The stock is trading near its 52-week low.