An initial public offering of the Bayer MaterialScience (BMS) is the most likely option for the Bayer group to separate out the plastics subgroup as it hasn't received any attractive offers from potential buyers, group CEO Marijn Dekkers said in an interview with the news agency Bloomberg.

"We prefer an ipo over a spinoff," Dekkers said, reiterating the company's stance since announcing the plans in September 2014. "We think that the size of the business, how it's positioned with its cash flow makes for a very good public company."

At the same time, the CEO added, "we have a fiduciary responsibility to look at other options if they would come up. They have not really come up, though there's always people who knock on your door."

Bayer expects to wrap up plans for a flotation by September of this year, and the launch is targeted for by mid-2016 at the latest. The transaction is expected to create Europe's fourth-largest chemical company with more than €12 billion in annual sales.

Commenting on analyst speculation that Bayer could use the proceeds from the BMS flotation to make an acquisition in animal health, Dekkers said: "We've always looked at different animal-health opportunities that have come and gone. It's a very attractive business for us, and we've always looked with interest in it. It hasn't happened with us yet."

Zoetis, the market leader in animal health and formerly part of Pfizer, has been mentioned as a takeover target for the German group.