Reuters reported earlier this year that Japan's fourth-biggest drugmaker by sales had hired JPMorgan to advise on the potential sale of the unit, Daiichi Sankyo Healthcare.

The company denied it was negotiating a sale.

"Although Daiichi Sankyo is constantly examining the potential for a variety of strategic developments with the aim of sustainable business growth, this reporting is not correct," it said in a statement.

Daiichi Sankyo is focusing on developing cancer treatments to offset a revenue drop following patent expirations of its mainstay blood pressure drug.

In the year through March 2019, the OTC unit generated 66.4 billion yen in sales. The group's total sales reached 930 billion yen.

The OTC unit makes popular energy drink Regain as well as Lulu Attack cold medicine and Gaster 10 stomach medicine.

(Reporting by Takashi Umekawa and Chang-Ran Kim; Editing by Stephen Coates and Christopher Cushing)