Exxon-Mobil has toughened its policy on using tankers more than 20 years old, shipbrokers said
. The company has adopted a policy of accepting vessels more than 20 years old only on a case-by case basis after senior chartering managers' approval.
The move mirrors several oil companies' increasing reluctance to charter older tankers in the wake of the break up of the fuel oil tanker Erika in December. Heavy pollution of French beaches resulted from the sinking.
A long period of ostracizing older vessels would be needed to drive them to the scrap yards, allowing freight rates to climb as shipping overcapacity erodes, brokers said.