Oil prices fell for the third consecutive day on Thursday as upbeat U.S. economic data failed to stanch concerns over bulging stockpiles in the world's largest energy consumer.

U.S. crude for October fell 63 cents to $70.80 a barrel by 1:00 p.m. EDT, down from a peak of $75 hit earlier this week. In earlier trading, crude fell below $70 to a session low of $69.83.

Brent crude lost 25 cents to $71.40 a barrel.

With a large supply overhang still intact across all petroleum groups, any bullish fundamental case must rely entirely upon future demand expectations, said Jim Ritterbusch of oil consultancy Ritterbusch and Associates.

The losses came after back-to-back reports this week showed crude oil inventories rose unexpectedly in the United States due to a surprise rebound in imports and continued soft demand from refiners.

The reports from the American Petroleum Institute and the U.S. Energy Information Administration reignited worries that the end of peak summer fuel consumption in the United States could spell further increases in stockpiles.

We have rising concerns about demand, with high inventories ... So it will be a tough ride for crude at this point, said PFGBest Research analyst Phil Flynn.

News that the U.S. economy had contracted more slowly than expected at 1 percent in the second quarter and a drop in U.S. jobless claims failed to keep oil from extending into its third day of losses.

Analysts said oil prices were unlikely to push much higher in the near term, after surging around 135 percent since February to a 10-month peak of $75 on Tuesday.

The market would need a strong reason to break $75, said Petromatrix analyst Olivier Jakob. It would need continuous support from equities and the dollar and further support from the statistics.

Oil also has not received much support from the 2009 Atlantic hurricane season.

Tropical Storm Danny, the fourth for this year, posed no foreseeable threat to the Gulf of Mexico oil area and was expected to stay well out in the Atlantic Ocean for the next few days, the U.S. National Hurricane Center said.

(Reporting by Richard Valdmanis in New York and Emma Farge in London; Editing by David Gregorio)