TOKYO - Japan's Shionogi & Co has signed a basic agreement with the government to supply an oral COVID-19 treatment it is now developing, the firm said on Friday.

The government is considering buying a million doses of the drug pending regulatory approval, the company added in a statement.

Shares of the company surged as much as 3.9% on the news, versus a decline of 0.3% in Tokyo's benchmark index.

Last month Shionogi sought approval of the pill, a protease inhibitor known as S-217622 that would become Japan's third antiviral approved for coronavirus patients, following those developed by Pfizer Inc and Merck & Co.

The company has global aspirations for the pill, saying last week it would launch a Phase III trial worldwide with U.S. government support. Chief Executive Isao Teshirogi has said production could reach 10 million doses a year.

(Reporting by Rocky Swift; Editing by Clarence Fernandez)