Oil prices fell on Wednesday after industry data showed US crude inventories rose last week when they had been expected to drop, even as a weaker dollar helped to limit deeper losses.

Crude futures have steadied this week after tumbling to three-months lows earlier in July on concerns that higher Iranian exports would add to an oversupplied market.

US crude held above $50 a barrel on Wednesday after dipping below that mark this week for the first time since early April. By 0528 GMT, West Texas Intermediate (WTI) for September delivery was trading 68 cents lower at $50.18 a barrel, after closing 42 cent higher in the previous session.

The WTI August contract, which expired on Tuesday, settled at $50.36 a barrel on its last day of trade, after slipping as low as $49.77 during the session.

September Brent futures were trading 48 cents lower at $56.56 a barrel, after rising 39 cents on Tuesday. Reuters technical analyst Wang Tao expected both benchmarks to rebound to $51.90 and $57.97, respectively.

Prices came under pressure after data from industry group American Petroleum Institute (API) showed U.S. crude stocks rose 2.3 million barrels in the week ended July 17.

In a poll by Reuters, eight analysts had forecast US commercial crude oil stocks fell 2.3 million barrels on average last week.

"Any indication of rising oil inventories in this week's EIA weekly report is likely to weaken oil prices further," analysts at ANZ said in a note to clients.

The US Energy Information Administration (EIA) report - more closely watched that the API figures - is due out at 1430 GMT on Wednesday.

Besides pressure from the nuclear accord between Iran and world powers, oil prices had also been weighed down over the past week as the dollar rose to three-month highs on prospects for a US interest rate hike later this year.

A stronger greenback makes oil more expensive for consumers holding other currencies, making them less likely to buy. - Reuters