NEW YORK (Reuters Life!) - Nearly 15 percent of all new marriages in the United States, twice the number from 1980, are between partners of different races or ethnicity, according to a new report.

The study by the Pew Research Institute is based on its own findings and US census data for 2008. It shows a doubling of the rate of interracial marriages for whites and a tripling for blacks.

"A record 14.6 percent of all new marriages in the United States in 2008 were between spouses of a different race or ethnicity from one another," according to the report.

"This includes marriages between a Hispanic and non-Hispanic as well as marriages between spouses of different races — be they white, black, Asian, American Indian or those who identify as being of multiple races or 'some other' race."

As late as 1967, 15 states had laws on their books banning marriage between blacks and whites, Pew said. In that year, the US Supreme Court declared those laws unconstitutional.

In following years, a large influx of Hispanic and Asian immigrants fueled the increase in mixed marriages, according to the Pew study.

Black intermarriage varied by gender. About 22 percent of black male newlyweds married outside their race, compared with just nine percent of black women.

The number was even higher for Asian women because 40 percent of female newlyweds married a non-Asian in 2008, double the number of Asian men.

The institute said marrying out was acceptable for 63 percent of US adults, according to the report.

Interracial marriage is more common among college-educated adults compared with people who had just completed secondary school. It is also more prevalent in Western states than in the South or Northeast of the United States.

"A third (35 percent) of all adults say they have an immediate family member of close relative who is married to someone of a different race," according to the institute.