* Buffett: "The financial panic is behind us"

* However, Buffett says economy still sputtering

* Bill Gates sees strength in technology, energy, medicine (Adds Bill Gates comment in paragraph four)

By Jonathan Stempel and Clare Baldwin

NEW YORK, Nov 12 (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.

He appeared at Columbia with Microsoft Corp (MSFT.O: Quote, Profile, Research) founder Bill Gates, the world's richest person and a Buffett friend and bridge partner.

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.