New Delhi, Oct 19 (IANS) Prime Minister Manmohan Singh Saturday praised Russia for assisting India in nuclear energy and said New Delhi wanted to scale up participation in Moscow's oil and gas sector.

Highlighting the special relationship between India and Russia, Manmohan Singh cited the Kudankulam nuclear power project in Tamil Nadu and Russian supply of hydrocarbons as concrete areas of cooperation.

"Indian and Russian companies have been holding negotiations on finalizing arrangements for Kudankulam units 3 and 4, and these contracts would be finalized shortly," Singh told ITAR-TASS news agency on the eve of his two-day visit to Russia.

"We deeply appreciate Russian assistance in development of nuclear energy in India when others had shunned nuclear commerce with us," he added.

While the second unit of the Kudankulam Nuclear Power Plant was in an advanced stage of construction, its first unit achieved criticality in July and should begin to provide electricity to the grid soon, he said.

Signalling the hydrocarbon sector as an "area of priority", Manmohan Singh said: "We are examining the feasibility of a proposal for direct surface transportation of hydrocarbons from Russia to India" as well as "enhancing our participation in the Russian oil and gas sector".

The prime minister also cited the development of the fifth generation fighter aircraft and the multi-role transport aircraft as two flagship projects in the India-Russia military-technical cooperation.

"These projects symbolize the transformation of our defence cooperation from a buyer-seller relationship of the past to one that now also involves joint design, development and production of advanced defence platforms."

On economic cooperation, an issue likely to be taken up during Manmohan Singh's visit is that of a free trade agreement with the Customs Union comprising Belarus, Kazakhstan and Russia.

"We have also proposed a Comprehensive Economic Cooperation Agreement between India and the Customs Union of Belarus, Kazakhstan and Russia which we hope would be initiated soon," he said.

Describing Russian President Vladimir Putin as the principal architect of the BRICS (Brazil, Russia, India, China and South Africa) grouping, he said there were no proposals for expanding it further.

On Syria, Manmohan Singh said India had worked together with Russia when New Delhi was a member of the UN Security Council. "It is essential that the Geneva-2 Conference (on Syria) be convened at the earliest."