Warren Buffett's company is taking an even bigger bite of Apple stock and adding to its sizeable stake in Phillips 66.
Berkshire Hathaway filed an update with regulators Monday on its roughly $130 billion U.S. stock portfolio.
Berkshire said it held 15.2 million Apple shares at the end of June, up from the 9.8 million share stake it first disclosed in the spring.
The Apple investment raises eyebrows because Buffett has always been reluctant to invest in technology companies, but it may have been the work of one of Berkshire's two other investment managers.
Berkshire now owns 78.8 million shares in oil refiner Phillips 66, up from 75.6 million.
It also cut its Wal-Mart investment to 40.2 million shares at the end of June from 55.2 million shares in March.
Explore further: Berkshire buys 5 pct of IBM, takes other stakes