NEW YORK (Bloomberg) - MF Global Ltd., the derivatives broker that's lost $2.8 billion in market value this year, plummeted 41 percent in New York after saying lower interest income and higher expenses will reduce net revenue this quarter to less than analysts' estimates.

Net revenue will be $360 million to $390 million, the Hamilton, Bermuda-based firm said in a statement yesterday, down from $413 million in the previous quarter and below the average analysts' estimate of $415 million. The reduction will cut earnings per share by almost half, to 17 cents, said Rich Repetto, an analyst at Sandler O'Neill & Partners.

Commissions per contract and the company's net interest margin may both have been "compressed," Mr. Repetto wrote in a note to clients today. "Neither development has positive implications for earnings."

Net revenue excludes interest and transaction-based expenses, according to the company.

MF Global declined $5.43 to $7.83, the biggest one-day drop since March 17.

That day, the shares fell 65 percent on concerns that clients were pulling money from the broker as similar concerns pushed Bear Stearns Cos. to near-bankruptcy.

MF Global announced the estimates after US exchanges closed yesterday.