Oil prices hovered below 100 a barrel today in Asia after a report showed US crude supplies jumped last week, a sign demand could be weakening.

Benchmark crude for February delivery rose 19 cents to $99.55 a barrel at midday Singapore time in electronic trading on the New York Mercantile Exchange.

The contract fell $1.98 to settle at $99.36 in New York yesterday.

In London, Brent crude was down 2 cents at $107.54 a barrel on the ICE Futures exchange.

The American Petroleum Institute said late yesterday that crude inventories rose 9.6 million barrels last week while analysts surveyed by Platts, the energy information arm of McGraw-Hill Cos., had predicted a drop of 2.3 barrels.

Inventories of gasoline added 1.9 barrels last week while distillates grew 600,000 barrels, the API said.

The Energy Department’s Energy Information Administration reports its weekly supply data later today.

Investors are also closely watching developments in the Persian Gulf. On Tuesday, Iran’s vice-president said his country will close the Strait of Hormuz, and cut off crude exports, if Western nations impose sanctions on Iran’s oil shipments.