Carl Icahn's Not So Hostile Herbalife Board Seat

Tickers in this article: HLF IEP

Since gaining seats to Chesapeake Energy's board in 2012, Icahn's influence has helped to spur asset sales, a change of the company's board structure and the departure of the company's founder Aubrey McClendon.

For Ackman, Herbalife's late-afternoon disclosure added to what was already a rough day.

Pershing Square's largest holding, J.C. Penney (JCP) , reported a near 30% deterioration in its sales for the fourth quarter , pushing the struggling retailer's shares nearly 17% lower in Thursday trading.

The earning miss raises serious questions about whether the company's turnaround plan, as mapped out by CEO Ron Johnson, will succeed .

-- Written by Antoine Gara in New York