West Texas Intermediate oil tumbled on Wednesday after increasing for two straight days, as the U.S. report showed that inventories in the country reached their highest figure since 1981. WTI for delivery in the next month slipped 52 cents to $93.68 a barrel on the NYMEX and was traded at $93.84 at 12:46 p.m. in London after it rose 84 cents to $94.20 yesterday, the highest closing price since April 3.