New York oil prices have sunk for the third day in a row, hitting a fresh three-month low as rising US stockpiles stoked demand concerns, dealers say.

New York's main contract, West Texas Intermediate (WTI) for delivery in December, slid to $US96.16 per barrel on Wednesday - the lowest point since July 1. It later stood at $US97.05, down $US1.25 compared with Tuesday's close.

Brent North Sea crude for December delivery shed $US1.56 to $US108.41 a barrel.

"The excess global supply of oil, combined with a weaker demand growth outlook, continues to weigh on prices," said markets analyst Fawad Razaqzada at traders GFT.

The US government's Department of Energy (DoE) on revealed Wednesday that American crude reserves had soared by 5.2 million barrels in the week ending October 18.

That was more than triple market expectations for a gain of 1.7 million barrels of crude, according to analysts polled by Dow Jones Newswires.

Rising stockpiles indicates weakening demand in the United States, which is the world's biggest oil consuming nation.

New York oil has tumbled since Monday, when a delayed DoE report showed crude inventories rose 4.0 million barrels in the previous week to October 11.

The outcome was far higher than expectations for a gain of 1.7 million barrels. That report had been delayed owing to the US government shutdown.

"Crude oil inventories increased by a further 5.25 million barrels last week, adding to the 4.0-million build we saw the previous week," added Razaqzada on Wednesday.

"Prices are thus likely to remain under pressure until inventories start falling, or if the Middle East crisis flares up again." New York crude futures had also fallen on Tuesday, dented by news that the US economy added 148,000 jobs last month. That was far less than the 183,000 forecast and stoked demand concerns once again.

Despite lower price levels, analysts contend that European benchmark Brent oil remains well supported by concerns over a potential disruption to Middle East supplies.

According to reports, an official from Libya's National Oil Corp on Tuesday said output had stabilised to around 600,000 barrels even as authorities struggle to end armed protests that cut shipments for months.

Libyan oil exports had plunged by more than 70 per cent after protesters, including policemen and border guards, forced the terminals to shut over demands for back pay.