Crude heads back towards $100 Oil rose back towards $100 a barrel yesterday in a furious rally triggered by relief over the latest deal to shore up European economies. The leading crude benchmarks each marked the biggest one-day gains since early 2009, when oil was bottoming amid the global financial crisis. Uncertainty about supplies persists as western sanctions tighten on Iranian oil exports. But analysts said the pace of the move reflected investors" shift back into riskier markets and away from the dollar, in which oil and most other commodities are priced, as European leaders agreed a new plan to help Spain and Italy grapple with the eurozone crisis. "Oil market fundamentals have not changed by $6 to $7 a barrel between yesterday and today," said Michael Wittner, commodities analyst at Société Générale in New York. It's the European summit and the action that they've appeared to have taken. ICE August Brent crude rose $6.44, or 7 per cent, to $97.80 a barrel. For the week, the benchmark closed up 7.5 per cent. Nymex August West Texas Intermediate rose $7.27, or 9.4 per cent, to settle at $84.96 a barrel, bringing weekly gains to 6.5 per cent. Crude remains well below the highs of the year. Brent ended the second quarter of 2012 down 20.4 per cent as an economic slowdown from the US to China left traders bracing for weaker demand. Production has also been strong, with Saudi Arabia pumping at a 30-year high of more than 10m barrels a day and US output growing thanks to its drilling renaissance. Yesterday's price jump came two days ahead of the formal introduction of a European ban on insurance of tankers carrying Iranian oil. The ban will prevent Asian refiners from buying insurance in London, which supplies 95 per cent of the world's maritime insurance. South Korea earlier this week announced it would stop importing Iranian oil as a result. Seoul is the fourth largest importer of Iranian oil. The sanctions, that come into force officially on Sunday, are already disrupting Iranian oil exports. Oil traders believe the country's exports had fallen by about 400,000 b/d, on top of the 600,000-800,000 b/d already hit by previous sanctions. JBC Energy, the Vienna-based consultancy, added that in addition, a strike by Norwegian oil workers, which has reduced supply in the critical North Sea market, was providing "upside to oil markets." The strike has cut production by up to 250,000 b/d, or nearly 15 per cent of Norway's oil production.