* Oil sinks on rising U.S. inventories, trade concerns
* OPEC cuts and Mideast tension prevent further falls
* Coming Up: Weekly U.S. oil rig count data at 1 p.m. (1700 GMT) (New throughout, adds comments, updates prices, changes dateline to NEW YORK; previous LONDON)
By Devika Krishna Kumar
NEW YORK, May 24 (Reuters) - Oil prices were steady on Friday ahead of long U.S. and UK holiday weekends, but were on track for its biggest weekly drop of the year, pressured by rising inventories and concern over an economic slowdown.
Brent crude rose 12 cents to $67.88 a barrel by 11:57 a.m. ET (1557 GMT) but the global benchmark remained on course for a weekly decline of about 6%.
U.S. West Texas Intermediate crude was unchanged at$57.91 a barrel. The benchmark was on track for a weekly drop of nearly 8%, the biggest weekly decline since December.
U.S. crude inventories have risen to their highest since July 2017, suggesting ample supplies in the world's top consumer , with prices also hit by worries that the U.S.-China trade conflict is developing into a more entrenched dispute.
U.S. inventories also rose due to more sluggish refinery rates than normal for this time of year. In particular, refining usage in the Midwest region plunged to its lowest levels in May since 2013.
Stockpiles at the Cushing, Oklahoma, delivery hub for U.S. crude futures were at the highest since December 2017, government data showed this week.
"U.S. businesses affected by the increased tariffs will be making decisions regarding purchases, inventories, etc., that are apt to force some downshifts in the U.S. economic growth path that could have implications for U.S. oil demand," Jim Ritterbusch, president of Ritterbusch and Associates, said.
"A decline below our expected next support level of $56 (for WTI) will likely associate with a further plunge in equities that would be heavily related to unresolved trade issues between the U.S. and China ... volatility across all markets will be heightened until some significant trade progress is seen."
Concerns over the health of the world economy linked to trade tensions have hit global markets this week, with the MSCI All Country index in line for a more than 1% fall in its third week in the red.
The markets will be closed on Monday in Britain for the Spring Bank Holiday and in the United States for the Memorial Day holiday, marking the de-facto start of the summer driving season.
The long U.S. holiday weekend is expected to see the second-highest travel volume on record since motorists advocacy group AAA began tracking holiday travel volumes dating back to 2000.
"Despite a rising national gas price average that is inching closer to the $3 per gallon mark, the vast majority of holiday travelers will drive to their destinations," AAA said last week.
Rising U.S. crude production has also weighed on oil prices. A shale boom has helped make the United States the biggest oil producer in the world, ahead of Saudi Arabia and Russia.
The United States on track to reach the 13-million barrels per day (bpd) milestone in the fourth quarter of 2019, according to the U.S. Energy Information Administration (EIA).
Weekly U.S. rig count data, an indicator of future output, from General Electric Co's Baker Hughes energy services firm will be released at 1 p.m. ET (1700 GMT)
Still, supply cuts - both voluntary and those resulting from U.S. sanctions - kept a floor under prices and some analysts expect the market to recover.
The Organization of the Petroleum Exporting Countries and allies including Russia, an alliance known as OPEC+, have been cutting supply since January to tighten the market and prop up prices.
U.S. sanctions on the oil industries of Iran and Venezuela, both OPEC members, have curbed their crude exports, reducing supplies further than envisaged in the OPEC+ deal.
Brent's price structure remains in backwardation, with prices for prompt delivery higher than those for later dispatch, suggesting a tight balance between supply and demand.
"It is reasonable to doubt whether Saudi Arabia will be willing to step up its output given the latest decline in prices," analysts at Commerzbank said. "We therefore expect to see higher oil prices again in the near future." (Additional reporting by Henning Gloystein Editing by Marguerita Choy and David Goodman)