Energy chiefs and political titans will gather in Moscow this week for a major conference that will highlight the West's desire to pursue oil investments in Russia despite the Ukraine crisis.

With oil prices hitting nine-month peaks owing to violence in Iraq, the 21st World Petroleum Congress, which occurs every three years, takes on even greater prominence.

Moscow, which is locked in its worst standoff with the West since the Cold War, is expected to use the week-long event to emphasise its leading presence on the world energy scene.

In Moscow, Opec secretary general Abdullah El Badri will be joined by about 5,000 delegates, including the chief executive of British energy giant BP Bob Dudley and bosses at Russia's Gazprom and Rosneft.

Russian President Vladimir Putin will make a speech today at the event that will bring public and private companies together with government agencies from 65 nations representing more than 95 per cent of the world's crude oil production and consumption. While various scheduled conferences and round tables present classic sector issues such as obstacles to financing and competition from renewable energy sources, developments linked to current geopolitical strains look set to grab the attention of markets.

Iraq, whose government is battling to regain control of the cities taken by militants, is the second biggest oil explorer in the 12-nation Organisation of Petroleum Exporting Countries after Saudi Arabia, and Opec pumps about one-third of the world's oil.

In Kiev, an urgent round of EU-brokered gas talks between Russia and Ukraine ended on Saturday night without an agreement.

Despite rising tension, Western energy companies are expected to use this week's event in Moscow to reiterate their desire to invest in exploration projects across Russia.-Reuters