NEW YORK (Reuters) –
Warren Buffett, perhaps the world's most admired investor, said on Thursday the financial panic that gripped the globe last year is a thing of the past, even as the U.S. economy's struggles persist.

"The financial panic is behind us," the world's second-richest person said at Columbia University's business school. "Our economy was sputtering, still is sputtering some."

Buffett, 79, nevertheless said there is greater opportunity for investments inside the United States than outside, noting that the U.S. economy is far larger than any other.

Last month, preliminary government data showed the U.S. economy expanded in the third quarter, the first three-month period of growth since the second quarter of 2008.

Nonetheless, the U.S. unemployment rate last month reached 10.2 percent, the first double-digit reading in 26 years.

Buffett last week made a big bet on the U.S. economy when his Berkshire Hathaway Inc (BRKa.N) (BRKb.N) agreed to pay about $26.4 billion for the 77 percent of railroad company Burlington Northern Santa Fe Corp (BNI.N) that it did not already own.

"There will be more people in this country, 10, 20, 30 years from now. They'll be moving more and more goods back and forth to each other and the most environmentally-friendly and cost-efficient way of doing that is railroads.

Overall, rail transport uses a third less fuel and puts far fewer pollutants into the atmosphere than trucks will. One train can supplant about 280 trucks, Buffett said.

Separately, Buffett advised the government not to coddle companies that need federal bailouts to survive or to preserve sufficient capital.

"More sticks are called for," he said.

Buffett gave Federal Reserve Chairman Ben Bernanke and U.S. Treasury Secretary Timothy Geithner "high marks" for how they managed the financial crisis.

Buffett has praised Bernanke in the past but has mocked Geithner's stress tests for banks.

(Reporting by Clare Baldwin and Jonathan Stempel; Editing by Tim Dobbyn and Bernard Orr)