May 30 (Reuters) - U.S. coastal cash crude grades strengthened on Friday, dealers said, as the U.S. oil rig count fell to the lowest since November 2021.

In an indication of future supply, U.S. oil rigs fell by four to 461 this week, energy services firm Baker Hughes BKR.O said on Friday.

Mars Sour WTC-MRS strengthened for the sixth consecutive session, firming 20 cents at a midpoint of a $1.4 premium. Light Louisiana Sweet WTC-LLS for July delivery strengthened 60 cents at a midpoint of a $2.75 premium, its firmest since late March.

U.S. crude oil output rose to a monthly record high in March, while demand for oil products declined to the lowest in a year, the U.S. Energy Information Administration said in its Petroleum Supply Monthly report on Friday.

Abroad, OPEC+ at its meeting on Saturday may discuss an increase in oil output for July larger than the 411,000 barrels per day (bpd) increases it made for May and June, sources familiar with OPEC+ talks told Reuters.

In refining news, the Dangote oil refinery in Nigeria, one of the world's biggest refineries, is expected to operate its gasoline-making unit at reduced production until October after a string of issues in recent months, industry monitor IIR Energy told Reuters.

* Light Louisiana Sweet WTC-LLS for July delivery strengthened 60 cents at a midpoint of a $2.75 premium and was seen bid and offered between a $2.65 and $2.85 a barrel premium to U.S. crude futures CLc1

* Mars Sour WTC-MRS strengthened 20 cents at a midpoint of a $1.4 premium and was seen bid and offered between a $1.30 and $1.5 a barrel premium to U.S. crude futures CLc1

* WTI Midland WTC-WTM weakened 5 cents at a midpoint of a 60-cent premium and was seen bid and offered between a 50-cent and 70-cent a barrel premium to U.S. crude futures CLc1

* West Texas Sour WTC-WTS weakened 5 cents at a midpoint of a parity and was seen bid and offered between a discount of 10 cents and 10-cent a barrel premium to U.S. crude futures CLc1

* WTI at East Houston WTC-MEH, also known as MEH, traded between a 70-cent and 90-cent-a-barrel premium to U.S. crude futures CLc1

* ICE Brent July futures LCOc1 fell 25 cents to settle at $63.9 a barrel

* WTI July crude CLc1 futures fell 15 cents to settle at $60.79 a barrel

* The Brent/WTI spread WTCLc1-LCOc1 widened 9 cents to to last trade at minus $3.30, after hitting a high of minus $3.10 and a low of minus $3.88

(Reporting by Stephanie Kelly in New York; Editing by David Gregorio)

((Stephanie.Kelly@tr.com))