US Edition Warren Buffett's investment fund Berkshire Hathaway has seen more than a billion dollars wiped off its stake in IBM after the IT giant missed profit targets in the third quarter.
IBM shares plunged by more than 8pc in pre-market trading on Wall Street on the news a third quarter performance that chief executive Ginni Rometty called "disappointing".
She said: "We saw a marked slowdown in September in client buying behaviour, and our results also point to the unprecedented pace of change in our industry."
Third quarter revenues were down 4pc at $22.4bn. Adjusting for the impact of currency fluctuations and the sale of IBM customer care outsourcing business, turnover was down 2pc.
The bottom line was much uglier for investors. Net profit from continuing operations was $3.5bn, compared with $4.1bn last year.
That meant quarterly operating earnings per share came in at $3.68, a long way short of the $4.32 expected by analysts. IBM also officially abandoned a target of earning $20 per share over the course of next year.
Berkshire Hathaway is the largest shareholder in IBM, with a 7pc stake, according to regulatory filings. It was worth more than a billion dollars less as the stock tanked before the bell in New York.
The losses come on the heels of Mr Buffett admitting he made a "huge mistake" by investing in Tesco. He slashed his stake in the supermarket last week.