UPDATE 2-Drugmaker Indivior prepares for pandemic hit to run into 2021

* Expects 2021 sales of up to $625 mln, assuming recovery in H2

* In the worst case, forecasts 2021 sales of $565 mln

* 2020 sales fall 18%, swings to operating loss on legal hit

* Shares down 1.3% in early trade (Adds details on legal settlements, newer drugs)

Feb 18 (Reuters) - Opioid addiction treatment maker Indivior on Thursday predicted 2021 revenue would slip on a difficult first-half after sales fell 18% this year due to cheaper rivals to its best-selling drug and disruption from the COVID-19 pandemic.

The company expects net revenue of up to $625 million, assuming that coronavirus restrictions that have kept patients away from hospitals and limited access to medicines will be lifted in the second half.

However, if those restrictions persist, net revenue is seen at $565 million, sending the London-listed company’s shares 1.3% lower at 147 pence in early trading.

The drugmaker, which gets the bulk of its sales from the United States, is focusing on growing newer treatments such as injectable opioid-addiction treatment Sublocade, and Perseris for schizophrenia to boost its fortunes.

It expects Sublocade sales of $185 million to $210 million in its most likely case, and Perseris net revenue of $17 million to $20 million.

“Accelerating the growth of Sublocade remains the biggest potential driver of value creation,” Chief Executive Officer Mark Crossley said, adding that Indivior aimed to hit peak sales of more than $1 billion for the treatment.

Indivior was grappling with drawn-out legal challenges and competition even before the virus outbreak hammered the healthcare sector. Former parent Reckitt Benckiser this month withdrew a $1.4 billion claim against the company to end a legal battle related to a U.S. probe into opioid addiction.

Indivior swung to an operating loss of $156 million for the 12 months ended Dec. 31 because of legal settlements worth $228 million. Excluding one-time items, operating profit was $88 million.

The drugmaker in September said it planned for up to $70 million in cost savings in 2020 as it restructures its supply channels. That programme was now complete, the company said on Thursday.

Revenue fell to $647 million from $785 million, in line with company’s prediction last month. (Reporting by Pushkala Aripaka in Bengaluru; Editing by Sriraj Kalluvila; editing by David Evans)