NEW YORK (Bloomberg) - MF Global Ltd., the world's largest broker of exchange-traded futures and options contracts, rose the most ever in New York trading after tumbling by two-thirds on Tuesday.

The "business continues to perform exceptionally well," CEO Kevin Davis told employees in a letter sent this morning and obtained by Bloomberg News. The shares plummeted on Tuesday on speculation that customers were withdrawing cash from MF Global after Bear Stearns Cos. sold itself to JPMorgan Chase & Co. to stave off bankruptcy.

"Events occurring at Bear Stearns over the weekend provided fuel for untruthful market rumors yesterday which considerably hurt MF Global's share price," Mr. Davis said in the letter. "I want to personally assure you that yesterday's rumors were entirely unfounded and that we maintain a strong capital position."

MF Global, based in Hamilton, Bermuda, climbed $2.12, or 35 percent, to $8.17 in New York Stock Exchange composite trading, the biggest jump since its July initial public offering. The shares fell $11.30 on Tuesday.

"All of our businesses have functioned effectively throughout the Asian day and on the European market," Mr. Davis said.

Tuesday's sell-off came about three weeks after an MF Global trader made what the company characterized as unauthorized wheat trades that lost the firm $141.5 million.

The day after the company announced the loss, Mr. Davis purchased 60,000 MF Global shares for about $1 million, according to government filings. Those shares are now worth about $490,000.

Other MF Global executives also bought thousands of shares after the wheat loss, including chief operating officer Christopher Smith and Simon Healy, the CEO of European operations.