The head of the world’s largest shipping market has expressed concern over the behaviour of one of the world’s biggest shipping companies after China’s Cosco apparently reneged on contracts with several shipowners worldwide amid a sharp market downturn.

Jeremy Penn, chief executive of London’s Baltic Exchange, spoke after several Cosco ships were reportedly arrested – ordered not to leave port – when angry shipowners and other creditors won court orders to have ships seized as collateral against unpaid fees. Such ships are often quickly released, since insurers generally provide assurances to courts about shipping companies’ ability to pay any damages awarded.

Cosco is the first large participant in the world’s vital dry bulk markets to be accused of backing out of previously agreed contracts while solvent since late-2008 when Australia’s Fortescue Metals refused to honour contracts to ship goods at high prices after a collapse in shipping rates. Fortescue was suspended as a member of the Baltic Exchange over its tactics.