Iran is in talks with Brazil’s Petrobras PETR4.SAPBR.N to explore two oil blocks in the Caspian sea and aims to finalize a deal by summer, an Iranian official was quoted as saying on Sunday.

Iran , which is facing mounting pressure from the West to abandon its nuclear ambitions, is seeking to attract foreign investors to help it develop its huge gas and oil reserves. But talks are often protracted and can take a long time to finalise.

Mahmoud Mohaddes, director of exploration of the National Iranian Oil Company, told the Teheran-e Emrouz daily $2 billion of foreign investment was needed to develop two Iranian oil fields in the Caspian Sea.

The state-owned Brazilian oil company said in March it would make a big push to expand its overseas exploration activities this year to countries like Iran.

‘Negotiations with Petrobras are still going on,’ he was quoted as saying at an energy conference in Paris. ‘The contract to explore two ... blocks in the Caspian Sea will be finalised by summer.’

State television said it would be Iran’s first oil and gas exploration operation in the Caspian Sea. The Iranian summer runs from June 22 to Sept. 22.

Iran is OPEC’s second largest producer but analysts have said it is in danger of slipping down the table of exporters as output stagnates because of a lack of investment, blamed on US sanctions and political interference.

Petroleo Brasileiro (Petrobras) has earmarked $5.6 billion for new international projects in 2007 through 2011. Its total planned exploration and production capital expenditure is over $40 billion.