Oil prices climbed off four-month lows on Thursday but the recovery was cautious with investors fretting that Opec-led supply cuts were not yet reducing record US crude inventories.
Brent crude, the international benchmark for oil, was trading at $50.84 a barrel by 0915 GMT, up 20 cents on the day and rebounding from Wednesday's slide to $49.71, it lowest level since Nov. 30 when Opec announced plans to cut output.
US light crude was up 20 cents at $48.24.
Brent remains well below this year's high above $58, hit shortly after Jan. 1 when the deal between the Organization of the Petroleum Exporting Countries and non-Opec states to curb supplies by 1.8 million barrels per day (bpd) came into effect.