March 14 (Reuters) - U.S. coastal cash crude grades eased on Friday, dealers said, in a week of more tepid price moves following whiplash the week prior when the U.S. imposed tariffs on Mexico and Canada.

Light Louisiana Sweet WTC-LLS and Mars Sour WTC-MRS eased to their weakest in over two weeks. Both grades had surged on the back of U.S. President Donald Trump imposing tariffs.

The tariff picture remained volatile, as Trump on Thursday threatened to slap a 200% tariff on wine, cognac and other alcohol imports from Europe, opening a new front in a global trade war that has roiled financial markets and raised recession fears.

Meanwhile, in an indication of future supply, U.S. energy firms this week kept the number of oil and natural gas rigs operating unchanged, energy services firm Baker Hughes BKR.O said on Friday.

In U.S. refining news, oil refiners are expected to have about 735,000 barrels per day of capacity offline in the week ending March 14, increasing available refining capacity by 194,000 bpd, research company IIR Energy said on Friday.

* Light Louisiana Sweet WTC-LLS for April delivery eased 45 cents at a midpoint of a $3.00 premium and was seen bid and offered between a $2.90 and $3.10 a barrel premium to U.S. crude futures CLc1

* Mars Sour WTC-MRS eased 55 cents at a midpoint of a $1 premium and was seen bid and offered between a 90-cent and $1.1 a barrel premium to U.S. crude futures CLc1

* WTI Midland WTC-WTM eased 10 cents at a midpoint of a $1.05 premium and was seen bid and offered between a 95-cent and $1.15 a barrel premium to U.S. crude futures CLc1

* West Texas Sour WTC-WTS was little changed at a midpoint of a 70-cent premium and was seen bid and offered between a 60-cent and 80-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 $1.40 a barrel premium to U.S. crude futures CLc1

* ICE Brent May futures LCOc1 rose 70 cents to settle at $70.58 a barrel

* WTI April crude CLc1 futures rose 63 cents to settle at $67.18 a barrel

* The Brent/WTI spread WTCLc1-LCOc1 widened to last trade at minus $3.63, after hitting a high of minus $3.56 and a low of minus $3.70

(Reporting by Stephanie Kelly in New York; Editing by Will Dunham and Nia Williams)

((Stephanie.Kelly@tr.com))