Warren Buffett’s Berkshire Hathaway (BRK.A) saw its profit decline 77% in the third quarter amid investment losses and declining revenue in some businesses.

Net income fell to $1.06 billion, or $682 per Class A equivalent share, from $4.55 billion, or $2,942 a share, in the same period last year.

Operating earnings per share fell to $1,335 from $1,655 a share in the three-month period a year ago, while revenue declined 6.7% to $27.93 billion.

While Berkshire saw a gain of $1.99 billion on investments and derivatives in the year-ago quarter, it took a $1.01 billion loss in the period this year amid the continuing credit crunch and overall financial crisis.

Also, the insurance business saw some losses. GEICO’s earnings before taxes and minority interests fell 27% -- to $246 million from $335 million in the same period last year. The same type of earnings at Berkshire Hathaway Reinsurance Group swung to a loss of $166 million in the quarter from a $183 million profit in the same period last year.

In addition, the insurance results include estimated losses of $1.05 billion from Hurricanes Gustav and Ike.

The company has suffered some equity losses, but said, “Berkshire has the ability and intent to hold these securities until fair value recovers.” That’s consistent with Buffett’s op-ed in the New York Times in which he encouraged investors to stick with the stock market in the long term.

The report also mentioned the high-profile recent investments in Goldman Sachs (GS) and General Electric (GE), which together totaled $8 billion.

Buffett is one of the most-respected investors in the country, and many people imitate his market picks and philosophy. He made news in recent months for a number of reasons, including his support of President-elect Barack Obama. Buffett has been advising Obama on economic and financial matters, and has even been rumored as a possible pick for Treasury Secretary, though has generally brushed off the suggestion.