Oil prices registered wide losses on Wednesday after a private survey on U.S. crude stocks showed a surprise addition of nearly 4.5 million barrels, confounding expectations of a fall of nearly half a million barrels.

Brent crude futures fell 62 cents, or 1.24% to trade at $49.33 a barrel, inching away from the psychological level of $50, while U.S. crude futures shed 81 cents, or 1.75% to hover around $47.26 a barrel.

Other commodities weren't much luckier, with gold futures giving up nearly three dollars, or 0.22% to trade at $1,343 an ounce, while silver prices slid six cents, or 0.35% to move around $18.85 an ounce.

As for the currency markets, no big moves were registered, with the pound edging up 0.20% against the dollar to 1.3222, while the euro dipped 0.10% to trade at 1.1295. The yen also shed 0.10% versus the greenback to 100.17.

Investors await some data later from the U.S., with existing home sales forecast to have slipped to 5.52 million units in July, from June's 5.57M, which could weigh on the greenback.

The official survey on U.S. crude stocks will be released later today, expected to show a drop of 0.5 million barrels, compared to the previous reading's 2.5M drop, but we could see a surprise buildup that punishes oil prices.