Wall Street stocks finished decisively lower on Friday following weaker than expected US jobs growth that pointed to a slowing economy.

The lacklustre job growth "played right into the market's worries about (economic) slowing," said Briefing.com analyst Patrick O'Hare, who noted that September has been a historically tepid period for equities.

After a muted opening, stocks lost ground throughout the session, finishing near lows for the day.

The S&P 500 ended at 5,408, down 1.7 percent for the day and 4.2 percent for the week.

The Nasdaq tumbled 2.6 percent to 16,690, while the Dow Jones shed 1.0 percent to 40,345.

The United States, the world's biggest economy, added an estimated 142,000 jobs last month, an increase from a poor July figure but below analysts estimates.

Its unemployment rate meanwhile declined slightly from 4.3 percent to 4.2 percent.

The report comes as markets eye an expected Federal Reserve interest rate cut. Following the data, futures markets increased the odds of a smaller 25-basis-point reduction in rates instead of one twice that size.

Friday's data was consistent with "a weakening labour market, but not weak yet," said Steve Sosnick of Interactive Brokers.

"The mood in the market has shifted toward risk off, and it's never 100 percent clear why markets shift their mood like this," Sosnick said.

Among individual companies, Broadcom slumped 10.4 percent on disappointment over the chip company's revenue forecast. (AFP)