Iran is experiencing "huge problems" exporting oil but there is unlikely to be a sharp drop in volumes after the European Union oil embargo comes into effect from July 1, the chief executive of oil trader Gunvor said.

Western financial sanctions have already cut into Iranian oil exports but there is considerable uncertainty over how the EU restrictions, due to take full effect in July, will impact the Islamic Republic's global sales.

As well as making Europe's around 740,000 barrels per day of imports illegal, it will also prohibit EU insurers from covering Iranian oil exports anywhere in the world.

Asked about Iranian oil exports, Torbjorn Tornqvist said on the sidelines of an FT commodities conference: "They have huge problems. The Iranians are suffering...It's going to be a gradual thing though. There won't be anything major in July."     

He added that Iran will be the single most important factor determining oil prices in 2012. Geneva-based Gunvor does not trade Iranian oil, he said.

Tornqvist said that global oil supplies are now more comfortable than at the start of year but said he does not expect futures prices to move into contango, a market structure typically associated with ample supplies.

"Oil stocks are much more comfortable now. Maybe there will be a mini contango at the front but along the curve, I doubt there will be a contango," he said.

Swiss-based Gunvor, co-owned by a Russian tycoon, said it had no plans to purchase further refining assets in Europe after agreeing to buy the Belgian plant of insolvent refiner Petroplus in early March. He said the plant will continue to process oil under Gunvor ownership and will not be converted to a storage terminal.

"We will run it as a refinery. It fits perfectly into our trading business at the moment," he said. "But refining is not an easy business and we still see structural overcapacity in Europe." - Reuters