U.S. stocks slid on Thursday as signs of further job market weakness and a disappointing Fed regional survey added to doubts that the economy was set for quick recovery.

The decline in stocks came in unison with sell-offs in other U.S. asset classes, including Treasury bonds and the dollar.

A reduced credit rating outlook for Britain also heightened investor concern that similar actions may loom elsewhere and reinforced fears that European economies may act as a drag on a global economic upturn.

The outlook downgrade of U.K. debt is being taken pretty negatively, said Rick Meckler, president of investment firm LibertyView Capital Management in New York. It sets a precedent for what could start to happen to a lot of the world, given the amount of spending that's going on.

U.S. Treasuries plunged on Thursday after the government said it would sell a massive amount of new debt next week, while the U.S. dollar earlier fell to its lowest level this year against a basket of currencies.

Shares of big manufacturers dropped, with United Technologies Corp falling 2.6 percent to $50.41, while Boeing Co shed 2.9 percent to $43.28. The big U.S. aircraft maker left its full-year forecast unchanged on Thursday.

The Dow Jones industrial average <.DJI> dropped 136.52 points, or 1.62 percent, to 8,285.52. The Standard & Poor's 500 Index <.SPX> fell 15.25 points, or 1.69 percent, to 888.22. The Nasdaq Composite Index <.IXIC> lost 35.44 points, or 2.05 percent, to 1,692.40.

Investors also pummeled technology shares. Apple Inc was the Nasdaq's top drag, down 1.6 percent at $123.85. Tech companies' fortunes are closely linked to a growing economy.

The S&P rallied nearly 40 percent from early March to a peak on May 8 but has now retraced some of those gains amid concerns over the economy and a series of large secondary stock offerings from banks. The index is now up 31 percent form a 12-year low on March 9.

U.S. government data showed ongoing claims rose to a fresh record as the recession battered employment, but the number of workers filing new claims for jobless aid declined 12,000 last week.

The Philadelphia Fed's survey of manufacturing conditions for the U.S. mid-Atlantic region contracted in May for the eighth straight month, but the deterioration improved slightly from April.

The economic data came one day after the U.S. Federal Reserve offered a more pessimistic view for economic recovery, deflating some of the optimism that had underpinned the stock market's recent rally from 12-year lows in early March.

(Reporting by Edward Krudy; Editing by Jan Paschal)