Iran, the fifth-largest crude exporter as recently as 2011, sold the least in 21 months in October as China , India , South Korea and Japan curbed purchases amid Western sanctions targeting the nation’s nuclear program. Imports from the Persian Gulf state fell by 45 percent to 715,000 barrels a day last month from September, the International Energy Agency , a Paris-based adviser to 28 nations, said in an e-mailed report today. The shipments, which the IEA estimates from tanker tracking, media reports and customs’ data, would be the smallest since January 2012. U.S. sanctions from the start of last year meant buyers of Iranian oil had to limit purchases or risk having their banks excluded from America’s financial system. Almost all the world’s tankers were barred from hauling the Gulf state’s fuel six months later when European Union rules took effect because the ships were insured by companies […]