Nutrition and weight loss company Herbalife estimated fourth-quarter profit and sales above analysts' expectations, sending its up 4 percent in premarket trading.
The company, whose stock has fallen 18 percent since the start of the year, also increased its share repurchase program and said it planned to raise $1 billion through a convertible note issue.
The announcement of better-than-expected results is a setback for activist investor William Ackman who said last week that he was sticking by his $1 billion short-selling bet that Herbalife is running a pyramid scheme.
(Read more: Bill Ackman: Herbalife's bad practices continue)
Big-name investors including Carl Icahn and George Soros have taken stakes in Herbalife, lining up against Ackman. Icahn is the company's biggest shareholder with a stake of 16.8 percent as of Sept. 30.