Pharmaceutical giant Teva is preparing to sack thousands of employees in Israel and the United States, including one quarter of its Israeli workforce, a business newspaper said Thursday.

Israel-based Teva, the world's biggest manufacturer of generic drugs, will sack 25 percent of its 6,860 employees in Israel and more than 10 percent of its 10,000-strong workforce in the US, Calcalist daily said.

The Israeli newspaper did not cite any sources for its report and a Teva spokesman contacted by AFP declined to comment on what he described as "market rumours".

Teva shares in the United States have taken a plunge this year as the company has faced harsh financial woes.

In December 2016, Teva agreed to pay US authorities $519 million to settle charges that it paid bribes to foreign officials to win business in Russia, Ukraine and Mexico.