Iran is seeking to close grain purchases using gold and oil as payment, and has paid yen for a large volume of wheat as it steps up efforts to beat sanctions that had started to choke imports of food staples, European wheat exporters said. Iran bought at least 2,00,000 tonnes of soft wheat on the world market last week for prompt delivery from private sellers — mostly of Australian origin — but some traders said the US could possibly account for part of the volume.