Looming new environmental regulations are triggering sharp divisions in the shipping industry between vessel operators investing billions of dollars to reduce emissions and others who want to stave off the financial impact by simply slowing down ships.

More than 100 shipowners, including some big Greek and German charter businesses, have signed a letter to the International Maritime Organization, an arm of the United Nations that works as the global marine regulator, calling for slower sailing speeds to cut greenhouse gas emissions.

If adopted, the measure could ripple across international supply chains, with products taking more time to be delivered and cargo owners paying more for transport costs because of the longer sailings.