Berkshire Hathaway, the investment firm of U.S. billionaire Warren Buffett, purchased $10.7 billion shares in technology giant IBM equivalent to 64 million shares.

With the buy-in, Berkshire now has a 5.5 per cent stake in IBM, making the company the second-largest shareholder after investment advisory group State Street, which has holdings of over 64 million shares.

Buffett told CNBC that Berkshire paid an average of $170 per share, which is 10 per cent lower than the Friday closing price of $187.38. The company actually bought the shares in March.

The Berkshire investment in IBM is a turnaround from Buffett's previous stand not to invest in high-tech firms because of the difficulty in predicting which technology business will bloom for the long-term. However, Buffett said he changed his mind after he read IBM's yearly reports and talked to IT department heads of Berkshire subsidiaries that IBM's focus is no longer on hardware but providing service.

Due to Buffett's winning streak in investment, where his company buys is closely watched by the public. The 81-year-old Buffett is listed by Forbes magazine as the world's third-richest man with a fortune of $50 billion.

Besides its investment in IBM, Berkshire also hiked its stake in American bank Wells Fargo, but Buffett did not provide additional details on how much shares his company bought.

Berkshire owns about 80 subsidiaries including companies engaged in insurance, railroad operations and utility.