What is the relationship between 'Warren Buffett' and 'Berkshire Hathaway' in the context of the input sentence.
Options: distributed by, legal form, director/manager, owner of

(AP) -- Warren Buffett is making the biggest bet of his long investment career, a $32.36 billion buyout of Precision Castparts in a deal that will continue to reshape his Berkshire Hathaway conglomerate.
owner of