Iron-ore shipping costs advanced the most in five weeks amid speculation that falling prices for the commodity in China may drive up demand and curb a vessel glut.

Rates for Capesizes carrying 150,000 metric tons or more advanced 8.7 percent to $6,300 a day, the largest increase since May 2, according to data today from the Baltic Exchange in London. Costs rose the most for charters starting and ending in western Europe and lasting as long as 45 days, which jumped 14 percent to $5,070, according to the bourse.

Stockpiles of the ore, a steelmaking raw material, are the lowest for the time of year since 2009, according to data from Beijing Antaike Information Development Co., a state-backed research company. Ore with 62 percent iron content fell 23 percent this year to $110.90 a dry ton, according to prices from The Steel Index Ltd. that are used to settle swap contracts.

“It’s logical that they are going to start restocking now,” Philippe Van Den Abeele, London-based managing director of Castalia Fund Management (U.K.) Ltd., an adviser to a hedge fund trading freight swaps, said by phone today. Freight prices have started rising and will continue to do so this year because fleet growth is now slowing while demand is gaining, he said.

Falling freight rates made it less attractive for owners to move vessels to the Atlantic region from Asia, limiting vessel supply, David Webb, a director at Arrow Chartering (U.K.) Ltd., said by e-mail.