Shares of J.C. Penney Company Inc. (NYSE:JCP) tumbled Friday in pre-market trading after the big department store chain's second-quarter earnings swung to a loss on falling sales, and the company cut its outlook for fiscal 2012.

The Plano, Texas-based company reported a loss of 37 cents per share or, adjusted one-time items, 19 cents per share. Standard & Poor's Capital IQ had forecast a profit of seven cents per share, adjusted for one-time items. Same-store sales or sales from stores open at least one year were down 22 percent for the three months ended July 28.

J.C. Penney Company Inc. said it no longer expects it will be able to meet its previously stated guidance for the full fiscal year.

Shares fell $1.95, or 8.91 percent, to $20.07 in premarket trading.