Washington ? The productivity of America’s workers soared by the largest amount in 20 years last quarter, raising hopes that the economic recovery is taking hold and businesses soon will be stepping up hiring.

The Labor Department reported Wednesday that productivity — the amount an employee produces per hour of work — rocketed at an annual rate of 9.4 percent in the July-to-September quarter, the best showing since the second quarter of 1983.

The figure, revised from a month ago based on more complete data, was even stronger than the government’s first estimate of an impressive 8.1 percent productivity growth rate and represented an acceleration from the brisk 7 percent pace in the second quarter.

“The gains in productivity are helping companies’ bottom lines so they can be less focused on cutting costs and more focused on expanding business and ultimately hiring more employees,” said Lynn Reaser, chief economist at Bank of America Capital Management. “This is very good news for the sustainability of the recovery.”

On Wall Street, the good news on productivity lifted stocks. The Dow Jones industrials gained 19.78 points to close at 9,873.42.

For the economy’s long-term health and for rising living standards, productivity gains are vital. They allow the economy to grow faster without triggering inflation. Companies can pay workers more without raising prices, which would eat up those wage gains. And productivity can bolster a company’s profitability.

That’s particularly important in the current economic climate. As profits improve, companies may be more willing to boost capital investment and hiring — two crucial ingredients for the recovery to be lasting.

In terms of productivity, “businesses have probably stretched their current work forces about as far as they can stretch,” said Stuart Hoffman, chief economist at PNC Financial Services Group. “If the growth in the economy continues, businesses would be required to add to their staffs, rather than expect current employees to do it all on a going-forward basis.”

The economy is estimated to be growing at a solid 4 percent rate in the current quarter. Although that would be a slowdown from the blistering 8.2 percent pace of the third quarter — the fastest in nearly two decades — analysts said such economic growth would be ample to spur hiring.

Traders work on the floor of the New York Stock Exchange. The Dow Jones industrials approached the 10,000 level Wednesday as investors eagerly picked up stocks on news of a strong productivity report. The Dow closed up 19.78, or 0.2 percent, at 9,873.42.

The nation’s payrolls are expected to grow in November by around 150,000, economists predict. If that happens, it would mark the fourth month in a row that hiring increased. The government will release November’s employment report on Friday.

During the economic slump, gains in productivity came at the expense of workers: Companies produced more with fewer employees. But in the third quarter, businesses pumped out more with a small increase in workers. The economy added a net 103,000 jobs during the quarter.

Companies’ output in the third quarter surged at a 10.3 percent rate, the biggest increase since the third quarter of 1983, and more than two times the 4.6 percent pace in the second quarter.

Workers’ hours in the third quarter increased at a 0.8 percent pace, the most since the first quarter of 2000, and a turnaround from the 2.2 percent rate of decline in the second quarter.

Businesses may be running out of ways to squeeze more out of existing workers to meet customers’ demands for goods and services, said Richard Yamarone, economist with Argus Research Corp. “Stronger job creation may be just around the corner,” he said.

Companies’ unit labor costs fell at a rate of 5.8 percent in the third quarter — good news for profit margins. That was better than the 3.2 percent rate of decline reported for the second quarter.

Workers’ hourly compensation adjusted for inflation rose at a 0.7 percent rate in the third quarter, down from a 3 percent rate in the previous quarter.

With the job market improving and the economy gaining traction, economists believe the Federal Reserve will hold a key short-term interest rate at a 45-year low of 1 percent at its next meeting Dec. 9. “The odds … do increasingly favor a revival in job creation,” a hopeful Fed Chairman Alan Greenspan said last month.