NEW YORK, Aug. 3 (Xinhua) -- Wall Street plunged Friday with the Dow Jones average dropping more than 280 points on credit woes.

Shares of Bear Stearns fell 5.9 percent after Standard & Poor lowered the credit outlook on the investment company to negative from stable due to its exposure to the subprime market.

Meanwhile, Sam Molinaro, Bear Stearns chief financial officer, said turmoil in the credit market was the worst he'd seen in 22 years.

The Labor Department said Friday that nonfarm payrolls rose 92,000 last month, less than the 132,000 jobs created in June and below the average forecast of about 135,000.

Unemployment was up to 4.6 percent, a six-month high, from 4.5 percent in June.

The Tempe, Arizona-based Institute for Supply Management, an organization of corporate purchasing executives, said that its index of business activity in the non-manufacturing sector registered 55.8 in July, down from 60.7 in June.

The Dow Jones average fell 284.84, or 2.12 percent, to 13,178.49. The Standard & Poor's 500 index dropped 39.39, or 2.68 percent, to 1,432.81, and the Nasdaq composite index fell 64.73, or 2.51 percent, to 2,511.25.