May 16 (Reuters) - Grades were little changed on Friday, dealers said, as investors weighed global oil supplies.

WTI Midland and WTI at East Houston WTC-MEH, also known as MEH, was unchanged, while Mars eased 10 cents.

Weak U.S. oil benchmark prices were set to spur drilling cuts in the United States, even as higher supplies were expected from Iran and OPEC+ producer group.

Baker Hughes said oil rigs fell by 1 to 473 this week, their lowest since January, while gas rigs fell by 1 to 100 in their first decrease since early April.

Oil and gas operators in North Dakota have indicated they plan to drop rigs and frac crews due to weaker oil prices, a move that is likely to impact output in the third-largest U.S. oil producer, the state's Department of Mineral Resources said on Friday.

* Light Louisiana Sweet WTC-LLS for June delivery firmed 50 cents to a midpoint of a $2.30 premium and was seen bid and offered between a $2.15 and $2.45 a barrel premium to U.S. crude futures CLc1

* Mars Sour WTC-MRS eased 10 cents to a midpoint of a $1.15 premium and was seen bid and offered between a $1.00 and $1.3 a barrel premium to U.S. crude futures CLc1

* WTI Midland WTC-WTM was unchanged at a midpoint of a 60-cent premium and was seen bid and offered between a 40-cent and 80-cent a barrel premium to U.S. crude futures CLc1

* West Texas Sour WTC-WTS eased 10 cents to a midpoint of a 10-cent discount and was seen bid and offered between discount of 20 cents and parity to U.S. crude futures CLc1

* WTI at East Houston WTC-MEH, also known as MEH, traded between a 60-cent and $1.00 a barrel premium to U.S. crude futures CLc1

* ICE Brent July futures LCOc1 rose 88 cents to settle at $65.41 a barrel on Friday

* WTI June crude CLc1 futures rose 87 cents to settle at $62.49 a barrel on Friday

* The Brent/WTI spread WTCLc1-LCOc1 widened 8 cents to last trade at minus $3.46, after hitting a high of minus $3.36 and a low of minus $3.46

(Reporting by Arathy Somasekhar in Houston; Editing by Will Dunham)

((arathy.s@tr.com))