WASHINGTON: A leading Indian researcher has suggested that the US must abolish the H1B visa and instead issue more green cards to prevent a reverse brain drain.

Vivek Wadhwa, an executive-in-residence at Duke University's Pratt School of Engineering, made the remarks after coming out with the "startling" statistics of a survey headed by him which found that immigrants were key founders in more than a quarter of all the engineering and technology companies set up in the US between 1995 and 2005.

Wadha said the study calls for substantial relaxations in US immigration policy, and made a strong case for Indians in particular, pointing out that Indians founded more engineering and technology companies in the US in the decade up to 2005 than the next four groups combined- those from the UK, China, Taiwan and Japan.

"Indians are among the best educated of all immigrant groups," he said, adding they accounted for 26 per cent of all start-ups, about 117,000 jobs and USD 14 billion in revenue in 2005. But that trend could be arrested or reversed as large numbers of skilled Indian immigrants are returning home because of the six-to-10 years it takes for their green cards or permanent immigrant status to arrive, Wadha said.

"This is a double loss for the US. One is that we lose good people. The second loss is that they will become our competitors," he notes, adding that this is true for many Chinese, Russian and European immigrants too.