America's position in the global software industry is under a major threat because of the strict US visa restrictions that have caused a decline in foreign computer science students, said Microsoft Chairman Bill Gates speaking at the World Economic Forum in Davos, said a Financial Times report.

Gates dubbed the alarming fall in the number of overseas students 'a disaster.'

The report said that America's status as 'the IQ magnet of the world' was in peril due to the tough immigration laws it has adopted.

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"There has been a 35 per cent drop in Asians coming to our computer science departments. It really is a very bad thing for a very key area," FT quoted Gates as having said.

The Microsoft chief pointed towards the sharp difference between emerging markets such as India and China, where about 40 per cent of students take engineering degrees, and the US, where the proportion is about 4 per cent, FT reported.

Even American universities are worried over the fall in the number of overseas students following the tough visa rules.

Meanwhile, Gates, whose net worth of $46.6 billion makes him the world's richest person, is also betting against the US dollar.

"I'm short the dollar," Gates, chairman of Microsoft, said in an interview at the World Economic Forum in Davos, Switzerland. "The ol' dollar, it's gonna go down."

According to a report on the website of Bloomberg, Gates's concern that the widening US budget and trade deficits are undermining the dollar was echoed in Davos by policymakers including European Central Bank president Jean-Claude Trichet and German Chancellor Gerhard Schroeder.

The trade deficit swelled to a record $609.3 billion last year, and the total US government debt rose 8.7% to $7.62 trillion in the past 12 months.

"It is a bit scary," Gates said. "We're in uncharted territory when the world's reserve currency has so much outstanding debt."

Gates reflected the views of his friend Warren Buffett, the billionaire investor who has bet against the dollar since 2002. Buffett said last week that the US trade gap will probably further weaken the currency.