Ackman goes to SEC in latest chapter of Herbalife saga

Bill Ackman
David Grogan | CNBC
Bill Ackman

Bill Ackman is taking his campaign against Herbalife to a new level, with sources telling CNBC that the hedge fund manager has filed a complaint with regulators against George Soros, who last week made a big investment in the nutritional supplement maker.

On Wednesday, news surfaced that Soros was taking a large long position in Herbalife. Ackman is now petitioning the Securities and Exchange Commission to address concerns that the legendary investor broke insider-trading rules by alerting other hedge funds about the big investment, sources say.

Bitter herb for Ackman
Bitter herb for Ackman   

Since last December, Ackman's Persing Square Capital has maintained an uncovered $1 billion bet against Herbalife, a position that has become increasingly squeezed as the stock has surged by around 60 percent. It has also embroiled Ackman in a bitter public war of words with billionaire investor Carl Icahn, who is long the stock.

—Reporting by CNBC's Scott Wapner, writing by Javier E. David.