US Cash Crude-Grades fall on last day of volatile roll trade period

Sept 25 (Reuters) - Physically traded domestic crude grades were down on Thursday, dealers said, on the third and final full day of the volatile roll trading period.

Traders use the three-day roll period to adjust their crude slates, square up positions and net out exposures following the expiration of the U.S. crude futures contract.

Prices to roll U.S. crude oil futures positions from October to November traded at a midpoint of 80 cents a barrel.

Grades fell despite a wide spread between West Texas Intermediate crude futures and global benchmark Brent, which usually makes U.S. grades more attractive to foreign buyers.

The discount WTCLc1-LCOc1 widened to as much as minus $4.36 a barrel on Thursday, suggesting an open arbitrage window

Light Louisiana Sweet WTC-LLS for October delivery was steady at a midpoint of a $2.20 premium and was seen bid and offered between a $2.00 and $2.40 a barrel premium to U.S. crude futures CLc1

Mars Sour WTC-MRS fell 40 cents to a midpoint of a 80-cent discount and was seen bid and offered between a 90-cent and 70-cent a barrel discount to U.S. crude futures CLc1

WTI Midland WTC-WTM fell 30 cents to a midpoint of a 80-cent premium and was seen bid and offered between a 70-cent and 90-cent a barrel premium to U.S. crude futures CLc1

West Texas Sour WTC-WTS fell 15 cents to a midpoint of a 30-cent discount and was seen bid and offered between a 40-cent and 20-cent a barrel discount to U.S. crude futures CLc1

WTI at East Houston WTC-MEH, also known as MEH, traded between a $1.50 and $1.70 a barrel premium to U.S. crude futures CLc1

ICE Brent November futures LCOc1 rose 11 cents to settle at $69.42 a barrel

WTI November crude CLc1 futures fell 1 cent to settle at $64.98 a barrel

The Brent/WTI spread WTCLc1-LCOc1 widened 4 cents to last trade at minus $4.36, after hitting a high of minus $4.33 and a low of minus $4.43