The settlement offers some respite to the London-listed drugmaker after failed efforts to stop generic versions of Suboxone Film, its top-selling drug and subject of the U.S. investigation, hit sales as it was further battered by the probe.

Reckitt and Indivior also agreed to drop all liabilities against each other and Indivior will not seek damages relating to its $600 million settlement with the U.S. Department of Justice and the $10 million it paid the Federal Trade Commission, the drugmaker said.

Its subsidiary pleaded guilty to a felony charge in July to resolve U.S. allegations that it had engaged in an illegal scheme to boost prescriptions of its opioid addiction treatment Suboxone Film.

Indivior also said on Monday the $50 million consideration it was paying Reckkit will be carried out over five years. It did not provide any further details on the settlement.

Reckitt did not immediately respond to a request for comment.

The United States has been cracking down on pharmaceutical firms it believes have fuelled the opioid addiction crisis in the country, and Reckitt agreed to pay up to $1.4 billion in 2019 to resolve claims against its former pharmaceuticals unit.

Indivior itself was indicted in early 2019 and accused of deceiving U.S. doctors and healthcare benefit programs into believing the treatment, itself a form of opioid, was safer and less susceptible to abuse than similar drugs.

The long-running U.S. investigations into the London-listed companies began much before Indivior was spun out from Reckitt in 2014.

Indivior shares closed down roughly 2% at 127.9 pence before the settlement was announced, whereas Reckitt ended the day 4.5% higher at 6,554 pence.

(Reporting by Pushkala Aripaka in Bengaluru, additional reporting by Samantha Machado; Editing by Anil D'Silva and David Evans)

By Pushkala Aripaka