Washington - The US Senate overwhelmingly approved an agreement on Wednesday allowing the United States to sell civilian nuclear technology and material to India, green-lighting the landmark accord for President George W Bush's signature.

The Senate voted 86-13 on the nuclear sharing agreement, reversing more than 30 years of US policy in exchange for international inspections of India's civilian nuclear energy programme. The House of Representatives passed the measure in a 298-117 vote on Saturday.

Bush placed the agreement at the top of his foreign policy agenda as he prepares to leave office in January and it has emerged as the centrepiece of increasingly strong diplomatic and economic relations between the two countries.

Bush urged Congress to act quickly on the deal that could position US firms to compete for billions of dollars of contracts in India's lucrative energy sector. The Senate could be considering amendments that would send the legislation back to the House for a second approval.

Bush and Indian Prime Minister Manmohan Singh signed the agreement in 2006 and the two countries have since been in complicated negotiations to implement it, mainly to ensure US technology does not enhance India's nuclear weapons capability.

Bush met with Singh Thursday at the White House and assured him the US administration would win prompt passage of the deal before the current congressional session ends in the coming days.

India's refusal to sign the Nuclear Non-Proliferation Treaty (NPT), which is designed to prevent the spread of dangerous nuclear material, complicated the negotiations and has been a sticking point in Congress.

Lawmakers opposed to the agreement argued it undermines international efforts to curb proliferation and sends the wrong message to countries like Iran and North Korea.

"This would create a dangerous precedent," Senator Tom Harkin, a Democrat, said in a debate just hours ahead of the vote.

The bill's advocates argue that India and the United States enjoy strong diplomatic and economic relations and the country's burgeoning population requires more effective and environmentally friendly ways to meet energy needs.

India "cannot slow the growth of energy production a the same time its population is growing," Senator Christopher Dodd, also a Democrat, said.

The White House had warned that failing to approve the deal would leave US companies out of India's energy sector. France signed a similar deal with India on Tuesday and Russia was looking for an agreement with New Delhi.

Earlier this month, an organization of 45 countries known as the Nuclear Suppliers Group (NSG) granted a US-backed waiver for India to purchase nuclear material on the international market. The waiver was required under rules banning sales to non-NPT members.

India also had to work out an arrangement for the International Atomic Energy Agency (IAEA), the UN nuclear monitoring body, for inspections of its civilian energy facilities but not its military related nuclear activities.

The deal had been hung up earlier this year in Singh's governing coalition. Smaller parties argued that the agreement compromised India's sovereignty because of US demands for the opening to international inspections of India's civilian nuclear reactors - but not military facilities.

That opposition softened in July after Singh prevailed in a parliamentary vote of confidence.

The United States had refused to cooperate with India's nuclear energy programme since the country first detonated an atomic bomb in 1974.

"For 34 years, India has suffered from a nuclear apartheid. We have not been able to trade in nuclear materials, nuclear reactors, nuclear raw materials," Singh said during his visit to Washington.

The US Chamber of Commerce has said the accord would allow US companies to benefit from the 150 billion dollars India is expected to invest in its energy sector through 2030. The Chamber of Commerce said the deal could create thousands of high-technology jobs in the United States.

An amendment offered by two senators, Byron Dorgan and Jeff Bingaman, sought to strengthen the US response in the event India tests a nuclear bomb, which it has not done a since 1998. But the amendment was defeated before the final vote on the bill.

The Dorgan and Bingaman amendment would have required the United States to cut off nuclear trade with India if the country tested a nuclear weapon.

The accord allows - but does not require - the United States to halt transfers if a test occurs. (dpa)