PARIS — A group of the world's top economies has agreed to release 400 million barrels of stockpiled oil, in a bid to counter soaring prices and the risk of a supply shock from the war in Iran. The agreement was reached following a meeting on Tuesday of the 32 members of the International Energy Agency, which include the U.S., Japan, Germany, the U.K. and France. It will represent the largest release of oil reserves in the body’s history, and is more than twice the 182 million barrels of oil