The rate of legal immigrants from India becoming US citizens has gone up from 56 per cent in 1995 to 65 per cent in 2005, a study said.

Statistics are showing that 133,000 Indians were in the soon to be naturalised category in 2005 of a total eligibility pool of 248,000, said the study released by the Pew Hispanic Center on Wednesday.

"We've seen dramatic changes in countries across the board," said Jeffrey Passel, the Pew Hispanic Center's senior research associate.

"Today's immigrants are interested in becoming US citizens," he said.

The number of legal immigrants from all over the world becoming US citizens grew to a record nearly 13 million between 1995 and 2005, it said.

More than half of the nation's legal immigrants are now naturalized citizens, "the highest level in a quarter century and a 15 percent increase since 1990," when the proportion of naturalized immigrants reached historic lows.

Since 1995, the average number of yearly naturalizations has surpassed 650,000, compared with 150,000 in 1970, it said.

The study has shown that among the immigrants who are eligible to become citizens by 2005, 77 per cent from the Middle East had already done so, Asia (South and East Asia) coming away in the second place with 71 per cent followed by 69 per cent for Europe and Canada and 46 per cent for Latin America.