Oil prices fell on Tuesday after eking out gains in the previous session, with the United States set to enter the lower demand autumn season and Asia's leading economies continuing to show signs of slowing down.

Oil prices edged up Tuesday after the release of bullish US economic data and as traders placed bets on the prospect of falling crude stockpiles.

But a rout that has dominated the past six weeks remains in force, analysts say, and US West Texas Intermediate (WTI) crude and internationally traded Brent have dropped back again.

"Any recovery in WTI prices from a six-year low may be short-lived with the US entering the slow demand period in September," ANZ bank said on Wednesday.

US crude futures were trading at $42.46 per barrel at 0339 GMT, down 16 cents from their last settlement. Brent was down 22 cents at $48.59 a barrel.

"The recent drop in the price of oil confirms ... the global commitment producers have to their current levels of (high) output," said Scott Cockerham, managing director Houston-based Conway MacKenzie's Energy Advisory Services.

"Could we see $30 oil in the next 15 months? Absolutely, and headlines like China's recent yuan devaluation and the prospect of sanctions on Iran being lifted will only contribute to such volatility," he said.

Cockerham added that a slowdown in US drilling would not pull down global supplies until 2017 and prices would likely remain low and volatile before then.

China's Commerce Ministry said on Wednesday it cannot rule out falling exports in the coming months, after data showed exports tumbled in July, and the ministry said the country's foreign trade was facing a severe situation and uncertainties.

Exports in July tumbled 8.3 per cent from a year earlier, their biggest drop in four months and imports fell 8.1 per cent from a year earlier.

Despite the overall bearish market sentiment, some analysts expect a price rebound, driven by strong demand for refined products, particularly in Asia.

"Crude prices are setting the stage for a significant bounce from the recent downturn. Product demand growth for the remainder of the year remains constructive (in Asia), and products will get a lift from fall maintenance," US-based PIRA Energy said in a note to clients.

However, PIRA also said that Asian refinery margins would be slow to recover as the region remains oversupplied with oil products due to rising supplies from new refineries in the Middle East. – Reuters