NYSE

J.C. Penney Co., up $3.11 at $39.94

The department store operator reported a 36 percent fall in second-quarter profit amid a tough spending climate, but still beat Wall Street estimates.

MBIA Inc., up 90 cents at $11.22

Credit rating agency Standard & Poor's said it is no longer considering a downgrade for the insurance arms of the bond insurer, or its rival Ambac Financial Group Inc.

NRG Energy Inc., up $1.93 at $37.15

In a filing with the Securities and Exchange Commission, Warren Buffett's Berkshire Hathaway Inc. disclosed a new investment in the power wholesaler.

International Rectifier Corp., up $3.67 at $22.49

Chip maker Vishay Intertechnology offered to buy the California-based power management chip maker for $1.6 billion, or $21.22 per share in cash.

New York & Co., up 21 cents at $10.23

The retailer expects third-quarter profit near its year-ago results but said second-quarter profit more than doubled on better margins and promotions.

NASDAQ

Oplink Communications Inc., up $1.26 at $13.96

The fiber-optic component maker gave a solid fiscal first-quarter profit and revenue outlook though it posted a fourth-quarter loss from a year-ago profit.

Autodesk Inc., up $4.02 at $38.37

The maker of computer-aided design software trounced estimates for second-quarter profit and sales due to overseas expansion and foreign exchange benefits.

UAL Corp., up $1.50 at $14.18

Oil prices sank, boding well for jet fuel costs and boosting shares of the United Airlines parent, which also named a new chief financial officer.