WASHINGTON, Nov 22: The Bush administration has advised top US energy firms to start negotiations with their Indian counterparts for supplying nuclear components, officials said.

"We have advised US companies to start their business negotiations right away because we do not know when the final green signal comes through," undersecretary of international trade Franklin Lavin said.

In a video conference with Indian journalists, Mr Lavin also named some major companies interested in exploring the lucrative Indian market for nuclear deals.

Chief executives of nuclear energy majors, including GE Energy, Nuclear Energy Institute, Thorium Power, Westinghouse Electric, BWXT, ConverDyn and WM Mining Company are expected to arrive in India on Nov 28.

The US expects India to invest $100 billion on generating nuclear energy to meet its huge needs. Besides giants such as the General Electric and Westinghouse, some other international firms are also keen to enter the Indian market. France's Areva SA, Electricite de France and Co. top the list of non-American competitors.

Last week the US Senate approved the proposed deal for civilian nuclear cooperation with India. The bill is expected to pass a joint congressional session next month as well but suppliers have to wait for the clearance of the 45-nation Nuclear Suppliers Group.

The US is also helping India in seeking NSG approval. India has not yet signed the nuclear non-proliferation treaty while the NSG does not allowing selling reactors or nuclear components to non-NPT nations.