Updated from 4:06 p.m. ESTStocks ended mixed in another nervous session on Thursday, despite solid retail sales data and positive guidance from Sprint PCS ( PCS) and Ciena ( CIEN). The Dow Jones Industrial Average fell 51 points, or 0.6%, to 8537.92, while the Nasdaq rose 2.7 points, or 0.2%, to 1399. The S&P 500 fell 3.4 points, or 0.4%, to 901.53. Weighing on sentiment were reports that North Korea plans to immediately reactivate nuclear facilities that were shut down under a joint agreement with the U.S., Japan and South Korea. Another report said al Queda-related extremists might have procured nerve gas from Iraq. Meanwhile, OPEC has reportedly agreed to revise production quotas to 23 million barrels a day. January crude oil closed up 31 cents at $27.71 a barrel. Elsewhere, the dollar traded lower against the euro and yen, as the threat of a conflict in North Korea or war in Iraq encouraged sellers. The biggest drags on the Dow were International Paper ( IP), IBM ( IBM) and Merck ( MRK). Volume on Thursday was thin at about 1.2 billion shares on the Big Board and Nasdaq. "From a technical perspective, the easy money has been made in this market," said David Briggs, head of stock trading at Federated Investors. "We can expect some sideways movement." The government said retail sales rose 0.4% in November, in line with estimates. Excluding car sales, the increase was 0.5%, topping estimates by three tenths. Separately, the Labor Department said new claims for jobless insurance rose by 83,000 to 441,000, an eight-month high, in the most recent week. Two technology bellwethers were higher after raising guidance. Sprint ended up 7% at $14.55 after it said its PCS wireless division would produce about $100 million more EBITDA this year than previously estimated because of better collections and fewer bad debt expenses. It also sees better results in 2003. Ciena added 20% to $6.20 after saying it could see a 10% sequential increase in first quarter revenue. The estimate came in the same release the company disclosed a $755 million fourth-quarter loss. Networker JDS Uniphase ( JDSU) added 2.8% to $2.90, and Juniper ( JNPR) gained 2.2% to $8.25. Biotech Amgen ( AMGN) finished up 6.7% at $50.45, after it said strong sales of recently acquired products would lift 2003 earnings to $1.70 to $1.80 a share. Analysts had been expecting earnings of $1.65 a share. In negative news, Bristol Myers ( BMY) closed down 6.6% to $25.35 after The Wall Street Journal, citing current and former company executives, said it used accounting shenanigans to meet its financial goals in past years. Treasuries were slightly lower, with the 10-year note losing 2/32 to yield 4.01%. Overseas markets were mostly lower, with London's FTSE 100 losing 1% to 3935 and Germany's Xetra DAX falling 2.6% to 3112. In Asia, Japan's Nikkei shed 0.2% to 8709, while Hong Kong's Hang Seng added 0.3% to 9184.