Supertanker rates may surge if the oil price spread between contracts widens, encouraging traders to use them to store crude, Morgan Stanley said.
A $1 a barrel increase in the premium the third-month contract holds over the front month in Brent oil futures traded on the London-based ICE Futures Europe exchange can boost rates for very large crude carriers (VLCCs) by as much as $31,000 a day, Mr Ole Slorer, a Morgan Stanley analyst estimated.
The average shipping rate for VLCCs was $37,178 a day on April 30, according to the Baltic Exchange. The rate to ship oil to Japan from the Middle East was $48,962.
The premium the third-month contract holds over the front month, a formation known as a contango, rose to $1.88 a barrel the other day from 55 cents on March 17, according to data.
"Some vessels have moved to floating storage as we continue to see a solid contango and thus strong storage levels on both the dirty and clean side," Mr Slorer said.
A wider spread would also increase the Suezmax tanker rate by about $15,500 a day, according to the report. The rate was $49,441 a day on April 30.
Floating storage employs tankers that would otherwise be available to deliver cargoes. Traders store oil expecting to benefit from the contango structure in futures markets. Traders can make money when the difference in prices is greater than the cost to charter the ship.
VLCCs can haul about two million barrels of oil. Suezmax tankers can move about one million barrels.