Analyze the relationship between 'Warren Buffett' and 'Berkshire Hathaway' within the context of the input sentence.
Options: brand, owner of, operator, legal form

NEW YORK (Reuters) - Billionaire investing icon Warren Buffett said on Tuesday there are dozens of countries in which his sprawling Berkshire Hathaway Inc (BRKa.N) conglomerate would be interested in buying new businesses.
owner of