Bayer has announced the sale of 19mn Covestro shares at a value of €1.2bn.
The pharamceuticals and pesticides giant revealed the sale this week, with its stake in Covestro reducing from 40.9% to 31.15%.
Its decision is based on the company's desire to complete a full separation from the plastics producer in its medium term.
Barclays and CitiGroup are bookrunners on the trade, though Bayer will now hold off on placing more Covestro shares for 90 days.
The German group employs well over 100,000 workers worldwide and had turnover of €46.8bn in 2016.