Icahn has amassed a large stake in J.C. Penney: WSJ

NEW YORK (Reuters) - Billionaire investor Carl Icahn has quietly amassed a large stake in department store operator J.C. Penney Co Inc (JCP.N), The Wall Street Journal reported on Friday, citing people familiar with the matter.

The article said that while the exact size of the stake is unclear, one person said it is among Icahn's top five holdings.

Icahn could not be reached for an immediate for comment. J.C. Penney said it does not comment on rumors or speculation.

Icahn, a veteran investor, regularly takes large stakes in companies and then agitates for change. He has recently been active in pushing for changes at Biogen Idec (BIIB.O) and Motorola Inc (MOT.N), and in January was named nonexecutive chairman of auto parts supplier Federal Mogul FEMO.PK, which emerged from Chapter 11 bankruptcy late last year.

"I said generally the retailers -- when they were down a couple of weeks ago really badly -- were interesting," Icahn said in a Friday interview on CNBC. He declined to comment to CNBC whether he owned shares of J.C. Penney.

J.C. Penney Chief Executive Officer Myron Ullman has been leading a turnaround at the mid-tier department store operator, filling its stores with more fashionable merchandise and striking deals with designers to offer exclusive products.

But its shares have fallen roughly 20 percent in the past year as its core middle-income shoppers have been squeezed by the deteriorating U.S. housing market, high energy prices, rising food costs, and turbulence in the credit market.

Its December sales at department stores open at least a year fell 7.5 percent, and the company has warned that fourth-quarter earnings will be at the lower end of its previous forecast of $1.65 to $1.80 per share.

J.C. Penney shares rose $1.09, or 2.3 percent, to $48.50 on the New York Stock Exchange.

(Reporting by Nicole Maestri and Dane Hamilton)