According to the Labor Department figures, the US economy added only 142,000 jobs in September 2015, lowering the chance of an interest rate rise this year.
The number of jobs created in September was far lower than the 205,000 increase forecast by economists.
The July and August figures were revised down by a combined 59,000.
On October 2, Wall Street opened sharply lower, with the Dow Jones and S&P 500 indexes both down about 1.3%.
However, both indexes later recovered to be up about 0.5% and 0.6% respectively.
The poor figures also resulted in a rollercoaster ride for the FTSE 100, which ended the day up 0.9% at 6,129.9 points despite also turning negative in afternoon trading.
The Labor Department numbers reinforced fears that the China-led global economic slowdown is hitting America’s recovery, adding to doubt about whether the Federal Reserve will raise rates before 2016.
The number of new jobs for August was cut by 37,000 to 136,000 – in sharp contrast to the upward revision expected by economists.
The July total was also reduced, by 22,000 to 245,000.
The number of new jobs created in the US has averaged 198,000 a month for 2014 – below last year’s average of 260,000.
However, the unemployment rate held steady at 5.1%.
The jobless rate, which is derived from a separate survey of households, was unchanged only because 350,000 workers stopped looking for work last month and were no longer counted as part of the labor force.
The proportion of Americans who either have a job or are looking for one fell to a 38-year low, partly reflecting retirements of older workers from the baby boomer generation.
Average hourly wages fell by 1 cent to $25.09 during the month and were only 2.2% higher than the same month in 2014.
The data also knocked the dollar lower, with the pound rising 0.6% to $1.5238 after the numbers were released. Yields on government bonds also fell.
The Department of Labor has reported on September 4 that the US economy added 173,000 jobs in August.
This is the last unemployment report before September’s interest rate decision by the Federal Reserve.
The number of jobs was below the 217,000 predicted by analysts, although the Labor Department said that figures for August tend to be revised higher subsequently.
The unemployment rate fell to 5.1% – down from the July figure of 5.3%.
The rate is the lowest since April 2008.
Wall Street headed lower following the numbers, with the S&P 500 falling 1.3% and the Dow Jones industrial average shedding more than 200 points or 1.2%.
European stock markets, which had been trading lower before the data was released, extended their losses, with the FTSE 100 in London down 2% and indexes in Paris and Frankfurt dropping about 2.6%.
There were upward revisions to the number of jobs created in the previous two months, which added another 44,000 jobs. The revised figure for July was 245,000 jobs.
The weaker-than-expected August number could make Fed officials think twice about increasing rates when they meet on September 16-17.
Chris Williamson, chief economist at Markit, said the decline in the unemployment rate could be the clincher for a September rise.
However, he added: “The most likely scenario is one where the Fed waits a little longer in the light of recent economic and financial market instability, instead merely testing financial market reactions with rhetoric that a rate rise is increasingly imminent.”
One of the officials who will help make that decision said on September 4 that the US labor market had recovered sufficiently to warrant raising rates soon.
Richmond Fed President Jeffrey Lacker, who had called for a rate increase in June, said the US economy no longer needed rates to be so low.
Fed officials will also take into consideration volatile global financial markets and slowing growth in China.