Utilize the input text as a context reference, choose the right relationship between Berkshire Hathaway and Phillips 66 from the options. Options: 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.

Sat, Aug 29, 2015, 22:16 BST - UK Markets closed Berkshire Hathaway builds stake in refiner Phillips 66 Berkshire Hathaway builds stake worth nearly $4.5 billion in refiner oil Phillips 66 By The Associated Press | Associated Press – 2 hours 8 minutes ago 77.23 +2.21

Answer: owner_of