The number of US families struggling with poverty despite parents being employed continued to grow in 2011 as more people returned to work but mostly at lower-paying service jobs, an analysis report released on Tuesday shows.

More working parents have taken jobs as cashiers, maids, waiters and other low-wage jobs in fast-growing sectors that offer fewer hours and benefits, according to The Working Poor Project, a privately funded effort aimed at improving economic security for low-income families.

The result is that 200,000 more such working families - the so-called working poor - emerged in 2011 than in 2010, according to the report, based on analysis of the most recent US Census Bureau data.

About 10.4 million such families - or 47.5 million Americans - now live near poverty, defined as earning less than 200 percent of the official poverty rate, which is $22,811 for a family of four.

Overall, nearly one-third of working families now struggle, up from 31 percent in 2010 and 28 percent in 2007, when the recession began, according to the analysis.

"Although many people are returning to work, they are often taking jobs with lower wages and less job security, compared with the middle-class jobs they held before the economic downturn," the report said.

"This means that nearly a third of all working families ... may not have enough money to meet basic needs."

The findings come three years after the nation's recession officially ended in the second half of 2009.

Brandon Roberts, co-author of the report, said the results were somewhat of a surprise after Census officials last year said the US poverty rate had stabilized.

"As the economy has improved one would expect that the benefits of that improvement would to some extent tie to these low-income families, and we'd see a decrease or at least a stabilization in the numbers," said Roberts, whose project is funded by four groups, including the Annie E. Casey Foundation and the Ford Foundation, and focuses on state policies.

"But the reality, the data shows that the benefits of this - even though it's modest economic growth - it's not going to these low-income families," he noted.

The group's analysis adds to the body of data focused on the slipping US middle class even as there are signs of the nation's economy slowly coming back to life with improvements in the housing sector and lower unemployment rate.

For some Americans, the comeback has yet to begin.

Reuters