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.

Thursday, September 10, 2015 1:31PM IST (8:01AM GMT) (BW)(NY-21ST-CENTURY-FOX) National Geographic Society and 21st Century Fox Agree to Expand Partnership New Expanded Joint Venture Will Combine National Geographic Channels with National Geographic’s Other Digital, Media & Publishing, Travel and Licensing AssetsTransaction Substantially Increases Society Endowment to Nearly $1 Billion and Significantly Expands Program Resources New York, Washington, United States The National Geographic Society and 21st Century Fox announced that they have reached an agreement to expand their highly successful 18-year partnership through which they have owned and operated the properties in National Geographic Channels, a joint venture of domestic and international cable television channels which together reach more than 500 million households globally.

Answer: owner_of: National Geographic Society, National Geographic