Buffett firm's 4Q up 49 pct. on paper gains

Buffett recounted the fourth quarter and Berkshire Hathaway's 2012 performance Friday in his annual letter to shareholders.

The Omaha-based company reported $4.55 billion net income, or $2,757 per Class A share, in the fourth quarter on $44.72 billion revenue. That's up from $3.05 billion net income, or $1,846 per share, on $37.96 billion revenue the year before.

Jeff Matthews, who wrote "Warren Buffett's Successor: Who It Is and Why It Matters," said there were few surprises in Buffett's annual report because the company is doing well.

"I thought it was pretty boring, and that's good news," Matthews said.

The paper value of Berkshire's investments and derivatives soared to $1.7 billion in the fourth quarter, up from $382 million the year before. Buffett has said Berkshire's investment and derivative gains or losses can be misleading because the company rarely sells its investments, and the derivatives don't mature until about eight years from now.

Buffett says Berkshire's operating earnings, which exclude the value of derivatives and investments, are a better measure of performance. They improved 5.5 percent to $2.8 billion in the quarter.