Nasdaq computer company shares suffered some of the worst declines this week, to the point where they are down about 2 percent for the year. The Nasdaq composite closed at 2,643.73, down by 41.14, the worst decline in terms of percent of the major U.S. exchanges. Even Apple, whose announcement of a new operating system and iCloud Web-based hosting service at the World Wide Developers Conference this week spurred analysts to raise recommendations on the company, was down Friday afternoon by US$5.59 to $325.90.

The Dow Jones Industrials index slipped 172.45 points Friday afternoon, closing at 11,951.91, under 12,000 for the first time since March. The broad-based S&P 500 meanwhile, closed at 1,270.98, down by 18.02.

Reports about a weak housing and labor market have fueled fears that the recovery is sputtering out and will affect spending for a wide range of companies. A U.S. Federal Reserve survey this week, for example, said that residential construction and real estate continues to flag, and that wage increases are minimal even for skilled workers. The Fed's second round of stimulus, the purchase of $6 billion in bonds, is also ending, with no other government stimulus plan in sight.

Arguments between the European Central Bank and the German Finance Ministry over a new Greek sovereign debt rescue plan raised fresh concerns about the European economy as well.

But despite some trouble spots for IT, underlying news seems to indicate a fairly strong market. Networking equipment supplier Ciena, for example, on Wednesday said its . Excluding one-time gains and losses, net loss for the quarter was $22.4 million, worse than the net loss of $11.7 million in last year's second quarter.