German magazine Wirtschaftswoche first reported that Bayer was screening its pharmaceutical locations and that employees in Germany feared up to 1,000 jobs could be cut. The magazine said Bayer's board would look at the review at the start of June.
The spokesman for Bayer gave no details on the timeline for the review, given the title 'Super Bowl', and did not say how many jobs would be affected. He said Bayer routinely examined its R&D operations.
Bayer employs around 8,000 people worldwide in its pharmaceutical business. In November, it announced that it would combine its R&D operations into a new function.
Some of the German group's shareholders have voiced concern that Bayer risks neglecting its drugs business following its planed $63.5 billion (47.7 billion pounds) takeover of U.S. seeds group Monsanto, which won U.S. approval on Tuesday.
Bayer's pharmaceuticals business faces a threat to revenues when in 2024 when the blockbuster heart drug Xarelto loses its patent.
(Reporting by Caroline Copley; Editing by Edmund Blair)