Oil prices softened on Wednesday ahead of data expected to show rising crude inventories in the United States and as the dollar strengthened from last week's three-year lows.
The premium of Brent over WTI widened to almost $3.60 a barrel, having neared its narrowest in six months on Tuesday as concern about a bottleneck of Canadian crude imports underpinned U.S. futures.
Traders are awaiting the latest data on U.S. inventories from the American Petroleum Institute, set to be released at 4:30 p.m. ET and government figures due on Thursday at 11 a.m., both delayed a day due to a holiday on Monday.
U.S. inventory data is due later in the day and stocks are expected to have risen by 1.3 million barrels in the week to Feb. 16, according to a Reuters poll.