LONDON (Nov 5): Brent oil dropped to a new four-year low below $82 a barrel on Wednesday, a fifth straight day of losses, as weak economic data from top energy consumer China intensified worries about demand as a global supply glut grows.

Services sector growth in China weakened in October as new business cooled, a private survey showed, coming just days after data revealed sluggish factory growth in the world's second-largest economy.

Brent fell 75 cents to $82.05 a barrel by 0913 GMT, having earlier reached the day's low of $81.63, its weakest level since late 2010.

U.S. crude fell 43 cents to $76.76 a barrel, rebounding off a low of $75.84 hit in the previous session - its weakest since October 2011 - after data showed U.S. crude stocks unexpectedly fell last week as refineries boosted output.

"Supply is higher and demand expectations are being cut almost every day," said Hans van Cleef, senior energy economist at ABN Amro in Amsterdam.

Brazil's oil output reached a record 2.358 million barrels per day in September, up nearly 13 percent from a year earlier, national oil regulator ANP said on Tuesday.

Consistent supply from Libya and Iraq, where many expected production to be disrupted by conflict, has added to the downward pressure on prices.

Van Cleef added that dollar strength was weighing on oil. Oil, priced in dollars, becomes more expensive to holders of other currencies when the U.S. currency rises, denting demand.

The dollar index hit a new 4-1/2-year high on Wednesday.

U.S. crude stocks fell by 639,000 barrels to 374.9 million in the week to Oct. 31, compared with analysts' expectations for a increase of 2.2 million barrels, data from industry group the American Petroleum Institute showed.

The market is now awaiting weekly inventory data from the U.S. government's Energy Information Administration (EIA) later in the day for more clues on demand in the world's top oil consumer.

Oil prices on both sides of the Atlantic lost more than 2 percent on Tuesday after Saudi Arabia cut export prices to the United States, threatening to deepen a global supply glut that has driven crude prices down 30 percent since June.

A bleak outlook for Europe after the European Commission downgraded its forecast for euro zone economic growth over the next few years also weighed on oil prices.

Saudi Oil Minister Ali al-Naimi is making his first visits in years to fellow exporters Venezuela and Mexico, although tumbling oil prices are not the stated purpose of the trip, according to officials and sources.

Still, the travel plans come at a pivotal moment for Saudi Arabia and the Organization of the Petroleum Exporting Countries, which meets later in November to discuss how to respond to the rout in global oil prices.