The sources, who asked not to be named, said the agreement was due to be signed by US Secretary of State Condoleezza Rice and Indian External Affairs Minister Pranab Mukherjee in Washington.

The pact will provide India with access to US nuclear fuel, reactors and technology, overturning a ban on such trade instituted after India first conducted a nuclear test in 1974.

The India-US deal could open up around $27 billion in investment in 18 to 20 nuclear plants in India over the next 15 years, according to the Confederation of Indian Industry.

President George W. Bush is scheduled to sign into law US legislation that underpins the agreement on Wednesday, a week after the bill was ratified by the US Congress over the objections of non-proliferation advocates.

The Bush administration believes the agreement will secure a strategic partnership with the world's largest democracy, help India meet its rising energy demand in an environmentally sound way and open up a civil nuclear market worth billions.

Agencies