Pharmaceutical giant Bayer (BAYRY)  said today that it is cutting its holding in Covestro, a Bayer spin-off and high-tech polymer supplier, through an accelerated book building process with a targeted volume of 1 billion euros.

The move comes in conjunction with the German-based firm's acquisition of U.S. agrochemical firm Monsanto (MON)

Last year, Bayer agreed to buy Monsanto for $66 billion. It has said it planned to finance the deal by raising $19 billion in new equity and $38 billion of debt. It also secured $57 billion in bridge financing from five banks.

Bayer is offering 1 billion euros of bonds exchangeable into Covestro shares maturing in 2020. Barclays (BCS) and Morgan Stanley (MS - Get Report)  will be acting as joint book runners.

In the context of the placements, Bayer has agreed to a lock-up period of 90 days.

The decisions announced today will allow Bayer to further reduce its stake in Covestro, as it aims to achieve a full separation in the medium term.

Shares of Bayer were lower during midday trading on Tuesday.