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.

comScore and Rentrak have each done an admirable job of innovating in their respective segments of the market, and we applaud all efforts to bring further innovation to the industry as cross-platform measurement continues to escalate in importance."

Answer: owner_of: comScore, Rentrak