The number of unemployed in the US leapt to 9.4 per cent in May, its highest level in more than 25 years, government data has shown.

However, the US department of labour also said on Friday that the number of job losses in the same month fell to 345,000, its lowest rate since September, suggesting the ailing US economy could be improving.

Job losses in both March and April were also less than previously thought, with employers cutting 652,000 positions in March versus 699,000 previously reported and slashing 504,000 jobs in April, less than the 539,000 initially estimated.

Since the US recession is widely stated to have begun in December 2007, the US economy has lost more than six million jobs, with a total of 14.5 million Americans now out of work.

US stocks rose slightly in early morning trading after hopes the slowing in job losses pointed to a turnaround in the economy, with the Dow Jones Industrial Average rising 30.93 points, or 0.4 per cent, to 8,781.17 points in the first hour of trading.

'Normal pattern'

Commenting on the news, Christina Romer, a White House economic adviser, told Bloomberg Television on Friday that the unemployment rate would stay high for a while.

"Even as we see things start to stabilise and hopefully grow again, we do know that unemployment tends to lag, and so that the unemployment rate is going to be high and probably stay high for a while, precisely because that is sort of the normal pattern as we come out of recession," Romer said.

Most jobs lost in May were from factories, with 156,000 jobs cut - slightly up from the 154,000 jobs cut in April, while construction companies cut 59,000 jobs, down from 108,000 in April.

Education, healthcare, leisure and hospitality were among the industries adding jobs in May.

However, even with layoffs slowing, companies remain reluctant to hire until they feel certain that economic conditions are improving and that any projected economic recovery will last.

As the US recession continues, firms have turned to layoffs and other cost-cutting measures to survive the fallout, including keeping workers' hours low and freezing or cutting pay.