Warren Buffett's Berkshire Hathaway
The Omaha, Nebraska-based conglomerate typically reports the results ahead of its annual investor meeting this Saturday, which draws thousands of shareholders.
Morningstar analyst Bill Bergman said the delay took him by surprise.
It is always on the eve of the meeting, he said.
The spokeswoman, Carrie Kizer, said no date had been fixed for the earnings release, and could not give a reason for the delay.
Berkshire's class A shares were 3.7 percent higher at $92,260 in mid-afternoon trade, and class B shares rose 4.6 percent to $3,046.
(Reporting by Lilla Zuill, editing by Leslie Gevirtz)