LONDON, Aug 23 Reuters Oil prices dropped on Wednesday, as traders were cautious ahead of potentially gloomy manufacturing data and an annual meeting at Jackson Hole, where heavyhitter central bankers including from the United States will talk interest rates.

Brent crude was down 51 cents to 83.52 a barrel at 0738 GMT, while U.S. West Texas Intermediate crude was at 79.15 a barrel, down 49 cents.

Markets await hints on the outlook for interest rates when Federal Reserve officials and policy makers from the European Central Bank, the Bank of England and the Bank of Japan head to Jackson Hole, Wyoming, for an annual meeting later this week.

Investors are reluctant to take big positions ahead of the Jackson Hole symposium as they want to find clues for the next step by the U.S. Federal Reserve, said Hiroyuki Kikukawa, president of NS Trading, a unit of Nissan Securities.

Earlier on Wednesday, Japan posted shrinking factory activity for a third straight month in August, and the euro zone, France, Germany, Britain and the United States are set to release their own purchasing managers39; index PMI data later in the day.

What oil watchers should be concerned with is that all of the predictions of their manufacturing PMIs are under 50, therefore they are all in contraction territory and readings below expectations will sound warnings again of lower oil demand, said John Evans of oil broker PVM.

Crucial to shoring up oil demand over the rest of the year is China, the…