The Labor Department said fewer people applied for unemployment benefits last week, a sign that the job market is recovering. The four-week average for applications, a figure closely watched by financial analysts, fell to the lowest level in more than two and a half years.
In Libya, army units loyal to Libyan leader Moammar Gadhafi struck back at protesters in Tripoli and attacked a mosque outside of the city where many anti-government demonstrators had taken refuge. Rebels control much of the eastern part of the country, effectively splitting Libya into two.
The clashes sent oil up to nearly $100 a barrel Thursday. Libya is the world's 15th largest exporter of crude, accounting for 2 percent of global daily output. Traders are worried the revolt could threaten Libya's oil production and spread to other countries in the region, such as oil-rich Saudi Arabia.
The Dow Jones industrial average fell 10 points, or 0.1 percent, to 12,095. The Standard & Poor's 500 index rose 1, or 0.1 percent, to 1,308. The Nasdaq composite index rose 16, or 0.6 percent, to 2,738.
Bond prices rose, pushing their yields lower. The yield on the 10-year Treasury note fell to 3.45 percent from 3.49 percent late Wednesday.
Priceline.com Inc. jumped 9 percent after the online travel service reported a 73 percent surge in fourth-quarter earnings and raised its income forecast for the current quarter. The stock rose the most of any in the S&P 500 index.
Sears Holdings Corp. fell 5 percent after the company said its income fell 13 percent as its Sears department store chain continued to struggle. The company also named former IBM executive Lou D'Ambrosio as its CEO late Wednesday.
H&R Block Inc. rose 6 percent after the tax preparation company said it expected to report near break-even earnings in its fiscal third quarter.
Boeing Co. rose 2 percent after the Commerce Department reported a big surge in orders for aircraft in January following declines in November and December.
The Commerce Department also said sales of new homes fell significantly in January, another sign that the housing industry is still struggling.