U.S. Mars Sour cash crude differentials strengthened on Friday, dealers said, as disruptions in the Red Sea prompted market jitters and the U.S. oil rig count indicated lower future supplies.

An increasing number of tanker owners steered clear of the Red Sea and multiple tankers changed course on Friday, shipping data showed, as U.S. and British air strikes on Yemen overnight escalated an already highly volatile situation in the Red Sea.

The attacks were carried out from the air and sea in response to the Yemeni Houthi militia’s attacks on ships in the Red Sea, a vital shipping lane for global trade.

An early indicator of future output, U.S. energy firms this week cut the number of oil rigs by two to 499 this week, energy services firm Baker Hughes BKR.O said.

Money managers raised their net long U.S. crude futures and options positions by 16,141 contracts to 67,357 during the week to Jan. 9, the U.S. Commodity Futures Trading Commission (CFTC) said.

U.S. crude’s discount to the international benchmark Brent widened to as much as minus $5.53, the widest since late December. A wider discount makes U.S.-linked crudes more attractive to foreign buyers.

Mars Sour firmed 5 cents at a midpoint of a 40-cent premium, dealers said.

Sweet crudes like Light Louisiana Sweet and WTI Midland WTC-WTM weakened.

Light Louisiana Sweet for February delivery fell 15 cents at a midpoint of a $2.60 premium and was seen bid and offered between a $2.50 and $2.70 a barrel premium to U.S. crude futures

Mars Sour gained 5 cents at a midpoint of a 40-cent premium and was seen bid and offered between a 25-cent and 55-cent a barrel premium to U.S. crude futures CLc1

WTI Midland fell 5 cents at a midpoint of a $1.35 premium and was seen bid and offered between a $1.25 and $1.45 a barrel premium to U.S. crude futures CLc1

West Texas Sour was unchanged at a midpoint of a 65-cent premium and was seen bid and offered between a 40-cent and 90-cent a barrel premium to U.S. crude futures CLc1

WTI at East Houston, also known as MEH, traded between a $1.65 and $1.85 a barrel premium to U.S. crude futures CLc1

ICE Brent March futures rose 88 cents to settle at $78.29 a barrel

WTI February crude futures rose 66 cents to settle at $72.68 a barrel

The Brent/WTI spread widened last to minus $5.47, after hitting a high of minus $5.28 and a low of minus $5.53.
Source: Reuters (Reporting by Stephanie Kelly, Editing by Marguerita Choy)