Moscow: Russia's top oil producer Lukoil said that Mittal Investments had bought half of its Caspian Investment Resources subsidiary, paying $980 million and assuming about $160 million in debt.

"After the completion of the deal, which is expected in early 2007, Caspian Investments Resources Ltd. will become a joint venture of Lukoil Overseas and Mittal Investments," Lukoil said in a statement.

Mittal Investments is part of the Mittal Group controlled by Indian steel tycoon Lakshmi Mittal. Caspian Investment Resources is Lukoil's wholly owned subsidiary for international upstream projects.

It was same the vehicle Lukoil used to buy Canada's Nelson Resources last year.

Lukoil paid $2 billion for 100 per cent of Nelson in the face of opposition from many small investors, who said the Russian major was paying far less than the real value.

The deal, which had the blessing of the Kazakh government, was the biggest foreign acquisition by a Russian firm.

Lukoil has said it wants to expand further in Kazakh-stan, which has massive hydrocarbon reserves and is set to become an important global oil player as it aims to triple output to three million barrels a day by 2015.

Lukoil said that it would invest $550 million to $700 million within five years to boost Nelson's output, which stood at around 30,000 barrels per day at the time of the acquisition.