A CHINESE businessman named Zhao Danyang paid a record $US2.1 million ($A2.6 million) in a charity auction on eBay last year to win a lunch date with one of his heroes — Warren Buffett, the so-called Oracle of Omaha.

This was a chance to get close to the world's greatest stock picker, Mr Zhao says, and to pick his brain about investing, the global financial crisis and philanthropy.

But a day before the lunch, which took place on June 24 at the Smith & Wollensky steakhouse in New York City, Mr Zhao told the media he would offer Mr Buffett a stock tip of his own: a little-known Chinese retailer called WuMart.

"I didn't want to influence the market," Mr Zhao, 37, said. "It was just a tip from a friend."

But that's not how the market reacted to it. Even before Mr Zhao arrived for lunch, shares of WuMart were climbing. By the time he returned to China, the shares were about 25 per cent higher and Mr Zhao's stock holdings in WuMart (which he insists will some day be China's Wal-Mart) were worth about $US16 million more.

Bloggers in China are now feasting on Mr Zhao, who runs several investment funds in Hong Kong, pointing out how he cleverly turned what looked like an expensive $US2.1 million lunch date into a short-term gain of $US14 million.

"Zhao Danyang is very smart at manipulating the media," a blogger named Lao Pi said last week.

"He made his own stock go up dramatically."

But Mr Zhao plays down the tip, saying he simply slipped Mr Buffett a few copies of WuMart's annual reports during a three-hour lunch of seafood and steak, with about seven or eight other guests he was allowed to bring along, including his young son.

He said Mr Buffett, the chairman of Berkshire Hathaway, was friendly and curious about China, but probably thought nothing of the annual reports.

NEW YORK TIMES