By Svea Herbst-Bayliss
NEW YORK (Reuters) - Carl Icahn on Thursday put his money where his mouth is.
The billionaire investor said in a regulatory filing that he owns 14 million shares, or 13 percent, of weight-loss and vitamin company Herbalife Ltd.
After weeks of speculation over exactly what the famed corporate raider might be doing, Icahn spoke up and put himself on a collision course with William Ackman, a rival activist investor who called Herbalife a house of cards and said he sees the share price going to zero.
The two men famously tussled on cable television in late January when Icahn called Ackman a "major loser" and warned him of trouble ahead in the form of a major short squeeze.
Herbalife's share price surged 20.6 percent in the wake of Icahn's filing, trading at $46.15 after the market closed.
Icahn said he wants to meet with Herbalife's management "regarding the business and strategic alternatives to enhance shareholder value, such as a recapitalization or a going-private transaction."
The company said: "We welcome all parties who see the same value in Herbalife that we do."
One short squeeze has already occurred, experts said.
(Reporting By Svea Herbst-Bayliss with additional reporting by Martinne Geller and Sam Forgione; Editing by Xavier Briand)