* Trump bans travel to U.S. from Europe
* Oil dives into steepest contango since Feb 2015
* Graphic on revised demand forecasts: https://tmsnrt.rs/2TTFao7 (Updates prices, adds comment, graphic)
LONDON, March 12 (Reuters) - Oil prices fell on Thursday following surprise travel restrictions imposed by U.S. President Donald Trump in an attempt to halt the spread of coronavirus after the World Health Organization described the outbreak as a pandemic.
The slump in oil is being compounded by the threat of a flood of cheap supply after Saudi Arabia and United Arab Emirates said they would raise output in a standoff with Russia.
Brent crude was down $2.01, or 5.6%, at $33.78 by around 0930 GMT. U.S. crude was down $1.77, or 5.4%, at $31.21.
"Failure to stop a market-share war will fill global oil storage and Brent prices again will trade with a $20 handle by year-end," said Robert Ryan, chief energy strategist at BCA Research.
The two benchmarks are down about 50% from highs reached in January. They had their biggest one-day declines since the 1991 Gulf War on Monday after Saudi Arabia launched a price war.
Global shares also took a hit after U.S. President Donald Trump said the United States would suspend all travel from Europe as he unveiled measures to contain the coronavirus epidemic.
The surprise move is likely to mean a further drop in demand for jet and other fuels in an already battered oil market, although just how much is hard to quantify.
The six-month Brent contango spread <LCOc1-LCOc7> from May to November widened to as low as $6.40 a barrel, a level not seen since February 2015.
Contango is where the futures price of a commodity is higher than the spot price, prompting traders to fill tankers with oil to store for later delivery.
As many await to see who will break first in the Saudi-Russian price war, Ehsan Khoman, head of MENA research and strategy at MUFG, said: "We believe that both sides have enough financial capacity and sufficiently divergent goals to sustain the oil price war for many quarters, not months."
The U.S. Energy Information Administration (EIA) and the Organization of the Petroleum Exporting Countries (OPEC) have slashed forecasts for oil demand because of the coronavirus outbreak and now expect demand to contract this quarter.
"If the crisis persists for another two or three months, many companies will go bankrupt, especially those in the U.S. energy sector which also have to deal with an oil price war," said Hussein Sayed, chief market strategist at FXTM.
Weekly data on U.S. inventories showed minimal effects from the coronavirus pandemic so far. Crude stocks increased by 7.7 million barrels, but inventories of gasoline and diesel fell sharply, as refining runs remain at seasonally low levels.
(Reporting by Bozorgmehr Sharafedin in London, additional reporting by Aaron Sheldrick in Tokyo; editing by Jason Neely)