Mumbai: India is according the highest priority to investments in public works, including roads, airports and transport services, besides energy sector even as the country continues to keep almost all sectors open to foreign direct investment, prime minister Manmohan Singh told a meeting of British businessmen.

"Our effort is to ensure that India has a world-class infrastructure including ports, airports, roads, the transport services and a lot more investment in the power and other related energy systems. These are our highest priorities," he said.

"In infrastructure alone, our estimate is that we need an investment of about $150 billion in the next seven to eight years," he said while announcing that India would soon finalise a policy and put in place a regulatory and institutional framework for infrastructure sector.

India, Manmohan said, proposes to scale up investments to 32-34 per cent of its GDP to help achieve a 10 per cent annual economic growth. "We are currently investing about 30 per cent. So we need to increase the investment rate by about 2 per cent of our GDP," he added.

He asked UK businesses to "take a more vigorous, more dynamic, more aggressive interest" in investing in India. He said there was an enormous scope for cooperation between the investment communities of the two economies.

Richard Lambert, the director-general of the Confederation of British Industry (CBI), meanwhile, called for a free-trade pact between Britain and the European Union and India. Lambert, who heads UK''s leading organisation representing 240,000 businesses and 80 of the FTSE''s 100 companies, demanded a massive upgrading of Britain''s warm-if-slightly-underdeveloped business relationship with India to realise the full potential of economic links between the two countries.

CBI members employ around a third of the UK''s private sector workforce and is an important player in the construction of Britain''s policy and business architecture.

Lambert''s call came at the start of the India-UK Investment Summit, along with the annual summit meeting of prime ministers Tony Blair and Manmohan Singh under the terms of the September 2004 joint London declaration.