US Cash Crude-Mars Sour slips as refineries head into seasonal maintenance

Sept 8 (Reuters) - Prices for grades were mixed on Monday, dealers said, with Mars Sour trading lower as domestic demand slipped as refineries head into maintenance, and producer group OPEC+ opts to hike output again next month.

U.S. oil refiners are expected to have about 574,000 barrels per day (bpd) of capacity offline in the week ending September 12, decreasing available refining capacity by 143,000 bpd, research company IIR Energy said on Monday.

Offline capacity is expected to increase to 697,000 bpd in the week ending September 19, IIR added.

Meanwhile, eight members of producer group OPEC+ agreed on Sunday in an online meeting to raise production from October by 137,000 bpd, it said in a statement, much lower than the monthly increases of about 555,000 bpd for September and August and 411,000 bpd in July and June.

The following day, Saudi Arabia, the world's top oil exporter, cut the official selling price for the Arab Light crude it sells to Asia.

* 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 5 cents to a midpoint of a 5-cent premium and was seen bid and offered between a discount of 5 cents and 15-cent a barrel premium to U.S. crude futures CLc1

* WTI Midland WTC-WTM was steady at a midpoint of a $1.15 premium and was seen bid and offered between a 95-cent and $1.35 a barrel premium to U.S. crude futures CLc1

* West Texas Sour WTC-WTS fell 5 cents to a midpoint of a 25-cent premium and was seen bid and offered between a 15-cent and 35-cent a barrel premium to U.S. crude futures CLc1

* WTI at East Houston WTC-MEH, also known as MEH, traded between a $1.20 and $1.60 a barrel premium to U.S. crude futures CLc1

* ICE Brent November futures LCOc1 rose 52 cents to settle at $66.02 a barrel

* WTI October crude CLc1 futures rose 39 cents to settle at $62.26 a barrel

* The Brent/WTI spread WTCLc1-LCOc1 widened 10 cents to last trade at minus $4.14, after hitting a high of minus $4.04 and a low of minus $4.15