Aug 1 (Reuters) - U.S. coastal cash crude grades eased slightly on Friday, dealers said, as OPEC and its allies were set to likely approve another oil output hike on Sunday and as Venezuelan oil is set to return to the U.S. this month.

Key grade WTI Midland and WTI at East Houston, also known as MEH, were unchanged, while Mars Sour WTC-MRS eased 30 cents.

Eight OPEC+ members will likely approve another oil output hike on Sunday, sources said, with the group still debating the final size of the increase for September amid fears of further supply disruptions from Russia and a seasonal slowdown in demand.

Meanwhile, Chevron CVX.N expects its exports of Venezuelan crude to the United States to resume this month, the U.S. oil producer's CEO said on Friday, following a restricted license received this week from the Treasury Department to operate in the sanctioned country and do oil swaps.

U.S. oil rigs, an early indicator of future output, fell by five to 410 this week, their lowest since September 2021.

Meanwhile, U.S. oil refiners are expected to have about 224,000 barrels per day (bpd) of capacity offline in the week ending August 1, decreasing available refining capacity by 3,000 bpd, research company IIR Energy said on Friday.

* Light Louisiana Sweet WTC-LLS for September delivery eased 15 cents to a midpoint of a $2.10 premium and was seen bid and offered between a $1.70 and $2.50 a barrel premium to U.S. crude futures CLc1

* Mars Sour WTC-MRS eased 30 cents to a midpoint of a 20-cent premium and was seen bid and offered between parity and 40-cent a barrel premium to U.S. crude futures CLc1

* WTI Midland WTC-WTM was unchanged at a midpoint of a 35-cent premium and was seen bid and offered between a 20-cent and 50-cent a barrel premium to U.S. crude futures CLc1

* West Texas Sour WTC-WTS was unchanged at a midpoint of a 20-cent discount and was seen bid and offered between a 30-cent and 10-cent a barrel discount to U.S. crude futures CLc1

* WTI at East Houston WTC-MEH, also known as MEH, traded between a 45-cent and 85-cent a barrel premium to U.S. crude futures CLc1

* ICE Brent October futures LCOc1 fell $2.03 to settle at $69.67 a barrel on Friday.

* WTI September crude CLc1 futures fell $1.93 to settle at $67.33 a barrel on Friday.

* The Brent/WTI spread WTCLc1-LCOc1 narrowed 6 cents to last trade at minus $3.44, after hitting a high of minus $3.42 and a low of minus $3.56.

(Reporting by Arathy Somasekhar in Houston; Editing by David Gregorio)

((Arathy.s@tr.com))