Oil may be sending a message that the recession is easing up in advanced economies, the IEA said on Thursday, raising its estimate for global demand for the first time for many months.
The data suggested that this slight upward boost came from leading industrialised economies and particularly from activity in the United States.
A recent 20-dollar surge in the oil price and unexpectedly strong US consumption were among signals that the recession may be receding, the International Energy Agency said in its June report.
Some of the price rise was driven by investors on futures markets anticipating trends on stock and money markets, and the price surge appeared "difficult to justify from fundamental factors alone," the IEA warned.
But overall data did suggest that industrial demand was picking up although consumption by the transportation and services sectors remained depressed.
"While rapid price swings can prove destabilising, higher prompt prices, if symptomatic of a gradually recovering global economy, in themselves may be no bad thing," and might encourage investment in oil production.
"By contrast, demand for transportation fuels remains very weak, suggesting that other economic sectors, notably services, are still constrained."
The benchmark price of New York oil was 71.89 dollars per barrel in London on Thursday, a gain of 56 cents since the closing price on Wednesday, but at one point had risen to 72.30 dollars, the highest since October.
"Demand for transportation fuels remains significantly subdued," the IEA said although the contraction of demand for gasoline (diesel) was slowing, probably because the US driving season was about to begin.
Referring to a sharp cutback by Americans in their driving last year, the IEA said that the trend now "suggests that this year, contrary to 2008, will likely feature a driving season," but the long-term increase of US demand for diesel was likely to slow sharply because of new legislation to tighten fuel-efficiency standards.
But the IEA also noted comment by some analysts that "the use of commodities as a hedge against the spectre of resurgent inflation and a weakening dollar will perpetuate the incentive to build inventory, squeeze the prompt market and risk a difficult-to-break vicious circle of upwardly spiralling prices."
And there was some evidence "that China was buying more crude for strategic storage during April and May."
It said that Chinese demand surged by 6.5 percent on a 12-month basis in April pointing to "a partial industrial revival".
But it warned that if activity remained subdued and global imbalances were not addressed for some time "China could well find itself facing excess capacity, inventory draws, a rise in non-performing loans and even deflation."
In Japan a "green shoot" of firmer demand, which had plummeted 18.6 percent over 12 months, "could well prove to be short lived."
Raising its estimate for global oil demand this year by 120,000 barrels per day from the figure in the May report, the IEA said this reflected "stronger-than-expected early-year OECD demand."
It said its revisions "do not necessarily imply the beginnings of a global economic recovery, and may only signal the bottoming out of the recession."
It said: "While the bull run in prices since mid-February was largely driven by market sentiment that a recovery in the global economic outlook was nearing, the latest surge in crude oil markets was partly fuelled by signs of slightly stronger fundamental factors."
Global oil demand was now estimated to be 83.3 million barrels per day this year, up from 83.18 million barrels in the May report, to show a fall of 2.5 million barrels per day or of 2.9 percent from the level last year.
The IEA, the energy-monitoring arm of the 30-nation Organization for Economic Cooperation and Development, said it had raised slightly its estimate for OECD demand this year to 45.2 million barrels per day, to show a fall of 2.3 million barrels per day or 4.9 percent from consumption last year.
This was also 120,000 barrels per day higher than previously expected, signalling that the increase for the OECD accounted for all of the global increase.
The agency also said it had revised upwards OECD consumption in March by 650,000 barrels per day, to show a fall of 3.2 percent over 12 months instead of 4.5 percent calculated earlier. Three quarters of that revision was attributable to the United States.
However some of this might reflect a rebuilding of oil stocks held by industry, and the IEA said it was not factoring all such revisions into its estimates until stronger evidence emerged.
The agency said that members of the Organization of Petroleum Exporting Countries had raised their output again in May, by 160,000 barrels per day to 28.4 mpd.
And the so-called OPEC-11 countries had raised output by 110,000 bpd to 26.0 mpd, or 1.1 million barrels per day above the OPEC target of 24.85 mpd, confirmed at a meeting on May 28.