Berkshire Hathaway builds stake worth nearly $4.5 billion in refiner oil Phillips 66

Billionaire investor Warren Buffett's company has amassed a stake worth nearly $4.5 billion in Phillips 66 more than a year after trading a chunk of its holding in the oil refiner for a chemical business investment.

A regulatory filing says Berkshire Hathaway Inc. has accumulated about 58 million shares, which amounts to more than 10 percent of the Houston company's stock.

In late 2013, the Omaha, Nebraska, company agreed to trade about $1.4 billion of its Phillips 66 stock for one of the refiner's businesses that makes additives to help crude oil flow through pipelines.

Many investors watch Berkshire Hathaway filings closely because they like to copy Buffett's moves given his successful record.

Phillips 66 shares closed at $77.23 Friday and have advanced about 8 percent so far this year.