Berkshire Hathaway reported a 48.7 percent first quarter gain in operating earnings, to $5.3 billion, as its insurance underwriting business swung back into the green and railroads, utility and other businesses posted gains.
Because of accounting rule changes that apply to its $170 billion stock portfolio, however, the conglomerate recorded a first quarter loss of $1.1 billion compared to net income of $4 billion in last year's first quarter.
Berkshire marked down the value of those investments nearly $6.3 billion.
Warren Buffett had already warned shareholders in his annual letter about the accounting changes, saying the new rule could "produce some truly wild and capricious swings" in the value of the stock portfolio that would "swamp the truly important numbers that describe our operating performance."
Buffett, who is preparing to lead the company's annual shareholder meeting later on Saturday morning, told CNBC on Friday the company acquired another 75 million shares of Apple during the first quarter, adding to its already large holdings. It also exited its remaining holdings of IBM.