Oil prices dip on US crude build, Asia demand worries

Oil prices dropped on Thursday, extending losses from the previous session, as signals of higher supply from the United States met worries about lacklustre energy demand from Asia.

Brent futures fell 28 cents to $80.90 a barrel by 0001 GMT. U.S. West Texas Intermediate crude (WTI) lost 31 cents to $76.35 a barrel.

Both benchmarks fell over 1.5 per cent in the prior session.

WTI's front-month contract was also lower than the second month, a structure known as contango, showing investors expect prices to increase ahead. The front month's discount to the second month traded at minus 15 cents on Wednesday, the widest discount since July.

U.S. crude stocks rose by 3.6 million barrels last week to 421.9 million barrels, according to the U.S. Energy Information Administration (EIA), far exceeding analysts' expectations in a Reuters poll for a 1.8 million-barrel rise.

U.S. crude production held steady at a record 13.2 million barrels per day (bpd).

Meanwhile in Asia, China's oil refinery throughput eased in October from the previous month's highs as industrial fuel demand weakened and refining margins narrowed. Still, its economic activity perked up in October as industrial output increased at a faster pace and retail sales growth beat expectations.