It was the second such rebuke from the industry in the last 10 days, with leading trade bodies again calling for governments to compel their navies to use force to halt the crisis.

The reprimand came as the Bahrain-based U.S. Fifth Fleet said it had sent warships to shadow a hijacked Ukrainian-owned ship carrying tanks and arms, now anchored off Somalia's coast.

Two other ships seized by pirates, the Capt. Stefanos and the Centauri, are anchored in the same place, according to the U.S. Navy.

"If civil aircraft were being hijacked on a daily basis, the response of governments would be very different," top trade bodies and transport unions said in a joint statement.

"Yet ships, which are the lifeblood of the global economy, are seemingly out of sight and out of mind," said the groups, which include the International Chamber of Shipping, Intercargo, Bimco and oil tanker group Intercargo.

More than 90 percent of the world's traded goods by volume are carried by sea.

"This apparent indifference to the lives of merchant seafarers and the consequences for society at large is simply unacceptable," they said.

The groups said they were "utterly amazed" that governments were unable to secure one of the world's most important seaways.

Continued inaction risked causing a repetition of the crisis in the early 1970s when the Suez Canal was closed and merchant shipping was diverted round the Cape of Good Hope, they said.

That re-routing had major consequences for international trade, including higher transport costs and the maintenance of inventories.

Some countries do have naval taskforces patrolling in the region, but they are often prevented from taking an active role by their rules of engagement. (Reporting by Stefano Ambrogi, editing by Tim Pearce)