Oil drops on U.S. inventories and doubts over output cuts

LONDON (Reuters) - Oil prices dropped on Thursday on doubts over the ability of crude producers to agree to extend record output cuts, heightened by worries over a build in U.S. fuel inventories.Brent crude futures eased by 29 cents to $39.50 a barrel by 0839 GMT, heading for its first fall in six sessions. U.S. West Texas Intermediate (WTI) crude futures dropped 53 cents to $36.76.Saudi Arabia and Russia, two of the world's biggest oil producers, have agreed to support an extension into July..