Investing.com -- Crude futures were relatively flat on Thursday, one session after plunging more than 4%, as investors continued to digest a massive inventory build last week in domestic energy markets in the U.S.
On the New York Mercantile Exchange, WTI crude for May delivery traded in a broad range between $38.34 and $39.77 a barrel, before settling at $39.48 down 0.37 or 0.78% on the session. The front month contract for U.S. crude closed below $40 a barrel for the second consecutive session. WTI crude has rallied more than 35% from its level on February 11 when it hit 13-year lows at $26.05 a barrel. On the Intercontinental Exchange (ICE), brent crude for May delivery wavered between $39.21 and $40.63 a barrel, before closing at 40.40, down 0.07 or 0.17% on the trading day. North Sea brent futures have fallen slightly since reaching 2016 yearly highs last week when they surged above $42.50. Since briefly dipping below $30 in mid-February, brent crude has rebounded by more than 15%.
Meanwhile, the spread between the international and domestic benchmark of crude stood at $1.02, above Wednesday's level of 0.74 at the close of trading.
Investors continued to react to a sizable U.S. supply build from last week when crude stockpiles nationwide surged by 9.4 million barrels from the previous week, the second-highest weekly inventory build on the year. At 532.5 million barrels, U.S. crude oil inventories are at historically high levels for this time of year.
Elsewhere, officials from the Paris-based International Energy Agency (IEA) admitted on Thursday that a highly anticipated output freeze between four major producers could essentially be "meaningless," amid views that Saudi Arabia is the only member of the group which may be able to boost production by a considerable amount. In mid-February, Saudi Arabia, Russia and two other OPEC producers agreed to freeze output at January levels in an effort to stabilize crashing oil prices. The nations could finalize a deal next month at a meeting in Doha.
"Amongst the group of countries we're aware of, only Saudi Arabia has any ability to increase its production," the IEA's head of its oil industry and markets division said on Thursday. "A freeze on production rather meaningless. It's more some kind of gesture which perhaps is aimed...to build confidence that there will be stability in oil prices."
Despite the recent rally, oil prices are still down by more than 60% from their peak in June, 2014 at $115 a barrel.
The U.S. Dollar Index, which measures the strength of the greenback versus a basket of six other major currencies, jumped more than 0.30% to an intraday high of 96.39, before falling back to 96.17 in U.S. afternoon trading. The index is on pace for a five-day winning streak, one of its highest in a year.
Dollar-denominated commodities such as crude become more expensive for foreign purchasers when the dollar appreciates.