In the context of the input sentence, determine the relationship between 'Phillips 66' and 'Berkshire Hathaway'.
Options: product/material produced, position held, owned by, subsidiary

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
owned by