Dec. 16 (Bloomberg) -- U.S. Gulf oil premiums weakened as the difference between West Texas Intermediate and Brent narrowed.

The spread between the two benchmark crude futures for February delivery settled at $9.60 a barrel today. The January Brent contract expired yesterday. The difference between the January WTI and Brent contracts was $11.22 yesterday. The differential has narrowed 66 percent since reaching a record of $27.88 a barrel Oct. 14.

When Brent decreases versus WTI, it weakens the value of low-sulfur U.S. grades that compete with West African oil priced against the European benchmark.

Light Louisiana Sweet’s premium to WTI narrowed 90 cents to $10.50 a barrel at 3:45 p.m. in New York, according to data compiled by Bloomberg. Heavy Louisiana Sweet’s premium narrowed 85 cents to $10.25 a barrel.

Thunder Horse’s premium to WTI decreased $1.20 to $8.40. The premium for Mars Blend lost 20 cents to $7 a barrel. Poseidon’s premium narrowed 35 cents to $6.40 a barrel over WTI.

Southern Green Canyon’s premium decreased 90 cents to $5.85 a barrel and West Texas Sour’s discount was unchanged at 85 cents.

The discount for Western Canada Select was unchanged at $15.75 a barrel.

Syncrude’s premium narrowed 25 cents to $2.75 a barrel. Syncrude is a light, low-sulfur synthetic oil derived from the tar sands in Alberta.

--Editor: Bill Banker, David Marino

To contact the reporter on this story: Aaron Clark in New York at aclark27@bloomberg.net

To contact the editor responsible for this story: Dan Stets at dstets@bloomberg.net