Total SA’s Elgin platform leaked gas for a third day in the U.K. North Sea, and neighboring rigs were evacuated to guard against the risk of an explosion. The platform was evacuated and production halted after a “well control problem” caused a leak on March 25. Total has flown in outside experts to help stem the flow of fuel, which prompted Royal Dutch Shell Plc. to move staff from its neighboring Shearwater field. The Elgin and Franklin fields, which send oil and gas through the platform, supply about 15 percent of Forties crude, the biggest component of Dated Brent used to price more than half of the world’s oil. As well as gas, about 23 metric tons of condensate…