Nippon Yusen K.K. will slash spending on new vessels by at least ¥260 billion as rates to transport commodities slump due to the swelling global fleet.

The planned cut would reduce spending to ¥1.54 trillion over the six years to March 2017, Japan's biggest shipping line said Tuesday in a statement. Nippon Yusen and Mitsui O.S.K. Lines Ltd., which operates the world's largest merchant fleet, also lowered sales forecasts for the current fiscal year.

Returns from carrying dry bulk raw materials such as iron ore and grains have plunged this year as a glut of ships exceeds demand for cargoes, forcing Tokyo-based Sanko Steamship Co. to seek bankruptcy protection. Returns for capesize vessels, the largest commodity carriers, are down 81 percent since the start of 2012, according to the London's Baltic Exchange.