Gulf tanker incidents may raise shippers' costs, cut traffic Seizures of oil tankers near Iran could raise insurance rates for shipping companies and eventually reduce tanker traffic, according to energy and security experts

Recent seizures and attacks aimed at oil tankers in the Strait of Hormuz will raise insurance rates for shipping companies and, if unchecked, reduce tanker traffic in the vital waterway, according to energy experts.

Britain's foreign secretary said Iranian authorities on Friday seized two ships, one flying under the British flag, the other registered in Liberia. The events occurred in a passageway that carries one-fifth of the world's crude exports.

"If this kind of problem continues, you might see people start to shy away from the (Persian) Gulf or try to reflag — not be a British tanker," said energy economist Michael Lynch.

The near-term impact will fall most heavily on the shipping industry in the form of higher insurance rates, said Lynch, president of Strategic Energy & Economic Research Inc.

Richard Nephew, a Columbia University researcher who wrote a book on sanctions, also believes the tanker seizures could create "a real risk premium" for companies that operate in the Gulf and insurers that underwrite them.

"Certainly we've seen concern with this in the past on sanctions grounds, and I would imagine security groups would be a far more complicating element," Nephew said.

On Friday, Iran's Revolutionary Guard said it took the British tanker Stena Impero to an Iranian port because it allegedly violated international shipping regulations. An Iranian news agency said the Liberian-flagged Mesdar was briefly detained and then released after being told to comply with environmental rules.

The seizures marked a sharp escalation of tension in the region that began rising when the Trump administration withdrew from a 2015 nuclear deal with Iran and imposed severe restrictions on Iranian oil exports and other sanctions.

Many of the 2,000 companies operating ships in the region have ordered their vessels to transit the Strait of Hormuz only during the daylight hours and at high speed. But only a handful of the companies have halted bookings.

The tensions in the Gulf also pushed oil prices slightly higher. Brent crude, the international standard, rose 0.9% to $62.47 a barrel on Friday, while benchmark U.S. crude gained 0.6% to settle at $55.63.

There's a long history of shippers enduring threats in the region.

"There have always been little problems around the Gulf where people will say, 'You're in our territorial waters,' but usually that doesn't go so far as the seizure of tankers," Lynch said.