As of noon (1700 GMT), the Dow Jones industrial average was up 145 points at 15,901. The Standard & Poor's 500 index climbed 12 points to 1,787. The Nasdaq was higher by 29 points at 4,030.
All 10 industry groups in the S&P 500 were higher, led by energy and technology.
LSI Corp. rose after chipmaker Avago Technologies said it was buying the company for $6.6 billion. AIG was up after it announced the sale of its aircraft leasing business for about $5.4 billion.
The Federal Reserve said factory production accelerated in November as auto production surged. The gains show manufacturing is strengthening and could help boost economic growth.