This means Hispanic-Americans would make up nearly one-quarter of the US population, which is predicted to reach 420 million, from 282 million in 2000.

Non-Hispanic whites would make up just 50.1% of the population in 2050, compared to 69.4% four years ago.

Overall in the US, women will continue to outnumber men, the report says.

This is going to be the workforce that sustains us as a nation Sonia Perez National Council of La Raza

There will be 6.9 million more females than males in 2050, compared to 5.3 million more in 2000 - when the last census was taken.

While people of Hispanic origin are the largest minority group in the United States, a recent report suggested that they suffered economically compared to other US citizens.

The study, co-produced by the Consumer Federation, showed the average Hispanic household's wealth was $11,500 against $86,000 for US households as a whole.

'New outlook'

The Census Bureau report says that Asian-Americans, who now account for 3.8% of the US populace, would represent 8% of the population by mid-century.

Their numbers would increase from nearly 11 million to more than 33 million.

The number of Hispanic-Americans should rise from about 36 million to nearly 103 million, and their share of the US population would nearly double, from 12.6% to 24.4%, the census said.

The number of black Americans is expected to rise from 35.8 million to 61.4 million in 2050, representing a 71% increase.

Sonia Perez, of the National Council of La Raza - which advocates Hispanic interests, said: "We knew where the trend was headed.

"This is going to be the workforce that sustains us as a nation, so we can make choices today that are dramatically going to change the outlook 20 or 30 years from now."