Chinese ports will raise warehousing charges for iron ore starting June 1, the Wall Street Journal reported. The move is expected to lower iron ore spot prices after government requests for importers to clear stocks proved unsuccessful. Importers looking to profit from contract price rises had pushed iron ore stocks held at ports to record levels. Iron ore imports for the first four months of the year were up 15%, significantly higher than the increase in demand from steel mills, according to the China Iron & Steel Association. Earlier this month, the association called on iron traders to boycott iron ore supplies from Rio Tinto after the company allegedly told Chinese mills it couldn’t fulfill contracts, while simultaneously offering ore on the spot market.