A maritime group embroiled in a contract dispute with China’s Cosco has rubbished the company’s claim that it is following normal commercial practice in refusing to honour charter contracts, while Moody’s warned that the shipping dispute now threatens the creditworthiness of the entire dry bulk industry.

“If you have a contract, you have to honour the contract,” said George Achniotis, chief financial officer of Navios Maritime Holdings and a director of Navios Maritime Partners. “We haven’t seen it from anyone else.”

Cosco insisted on Friday that there was nothing unusual about the dispute, which has led to the seizure of at least three Cosco vessels . It is withholding charter payments for ships it chartered long-term for as much as $80,000 a day at the height of the dry bulk shipping boom in 2008. Average spot market rates to charter Capesize vessels, the largest class, stood at $16,716 a day on Friday.