Given the input sentence, please extract the subject and object containing a certain relation in the sentence according to the following relation types, in the format of "relation1: word1, word2; relation2: word3, word4". Relations include: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

"We have been evaluating the optimal way for the separation of the MaterialScience business and believe that an IPO delivers clear benefits for both Bayer and Covestro and their stakeholders," said Bayer chief executive Marijn Dekkers.

Answer: owned_by: Covestro, Bayer