US Cash Crude-WTI at East Houston trades at more than 2-1/2-year low on weak export demand

June 18 (Reuters) - The differential for WTI at East Houston WTC-MEH versus U.S. crude at the Cushing storage hub eased to its lowest in more than two and half years on Wednesday on weak export demand and backwardation in markets, dealers said.

WTI at East Houston eased to a 15-cent premium as the Brent/WTI spread WTCLc1-LCOc1 narrowed to as little as minus $3.08. A narrower spread, particularly under minus $4, cuts exports as it is less attractive for foreign buyers to purchase U.S. crude.

WTI Midland WTC-WTM fell 15 cents to a midpoint of a 10-cent premium.

Backwardation for U.S. crude has widened in recent days, meaning investors are not incentivized to store crude.

Medium sour grades such as Mars remained firm as refiners ran more crude to keep up with summer driving demand. Further boosting prices for medium sour crudes were lower supply of heavy Canadian crude as a result of wildfires, and of Venezuelan crude as a period granted by Washington to wind down purchases expired in late May.

U.S. oil refiners are expected to have about 228,000 barrels per day of capacity offline in the week ending June 20, increasing available refining capacity by 40,000 bpd, research company IIR Energy said on Wednesday.

* Light Louisiana Sweet WTC-LLS for July delivery fell 25 cents to a midpoint of a $2.25 premium and was seen bid and offered between a $2.00 and $2.50 a barrel premium to U.S. crude futures CLc1

* Mars Sour WTC-MRS rose 15 cents a midpoint of a $1.55 premium and was seen bid and offered between a $1.45 and $1.65 a barrel premium to U.S. crude futures CLc1

* WTI Midland WTC-WTM fell 15 cents to a midpoint of a 10-cent premium and was seen bid and offered between parity and 20-cent a barrel premium to U.S. crude futures CLc1

* West Texas Sour WTC-WTS fell 20 cents to a midpoint of a 75-cent discount and was seen bid and offered between a $1.00 and 50 cent a barrel discount to U.S. crude futures CLc1

* WTI at East Houston WTC-MEH, also known as MEH, traded between a 5-cent and 25-cent a barrel premium to U.S. crude futures CLc1

* ICE Brent August futures LCOc1 rose 25 cents to settle at $76.70 a barrel

* WTI July crude CLc1 futures rose 30 cents to settle at $75.14 a barrel

* The Brent/WTI spread WTCLc1-LCOc1 narrowed 5 cents to last trade at minus $3.13, after hitting a high of minus $3.08 and a low of minus $3.24