Ahead of the bell: Shares of Icahn's firm tumble

Shares of Carl Icahn's investment firm tumble after pricing stock offering at a discount

NEW YORK (AP) -- Shares of Carl Icahn's investment firm, Icahn Enterprises LP, tumbled before Friday's opening bell after a big stock sale priced at a 12 discount.

The offering, of 3.2 million depositary units that represent limited partner interests in the firm, priced for $63 each. The bank managing the deal may buy nearly 500,000 more shares, which closed at $71.49 Thursday.

News of such public offerings often weigh on company shares, as issuing new stock makes existing investors' holdings less valuable. Icahn Enterprises has about 104.9 million shares outstanding.

Proceeds will be used for general corporate purposes.

The billionaire investor is in a tiff with a rival, hedge fund manager Bill Ackman, over Herbalife Ltd. The dietary supplements company said Thursday that it will add two new members of Icahn's choice to its board, and that Icahn can increase his stake of 13.6 percent to as much as 25 percent. While Icahn has backed Herbalife, Ackman has a negative bet on the company and has accused it being a pyramid scheme.

Shares of Icahn Enterprises, which has subsidiaries involved in industries including auto suppliers, casinos and real estate, fell $9.34, or 13 percent, to $62.15 in premarket trading. The stock has gained 71 percent over the past 12 months.