The world’s largest shipping register withdrew its approval for Russia’s Ingosstrakh Insurance Co. to provide a key document enabling ships to enter ports. 

The Liberian Register — under whose flag 16% of the world’s ships by capacity sail — said in a circular that it no longer authorizes Moscow-based Ingosstrakh Insurance Co. to issue so-called blue cards. Blue cards provide proof of cover against risks including oil spills and collisions. They are essential for port entry. 

Last week, the UK sanctioned Ingosstrakh as part of a set of wide-ranging Group of Seven measures designed to target Russia as it continues its war in Ukraine. The firm has become an important provider of cover against spills and collisions for Russian oil exports, effectively displacing western entities. 

In practice, the Liberia’s move may well prove symbolic. There are only three vessels covered by Ingosstrakh that sail under the flag of Liberia and none of them are oil tankers, according to a vessel database maintained for the International Maritime Organization. However, the move reinforces a growing divide between the parts of the global shipping fleet that are able to serve Russia and those that can’t. 

Any ship with Ingosstrakh cover will receive a 90 day grace period, the circular said. 

Despite its name, the Liberian register is headquartered in the US. National shipping registries are a common feature of the international shipping industry, applying common sets of rules that vessels must stick to in order to fly a nation’s flag.