NYMEX-Crude ends down almost 4 pct on Japan crisis

* Japan nuclear crisis worsens, radiation released

* Pro-Gaddafi forces retake oil towns, marching east

* Bahrain declares martial law to quell uprising

* IEA trims demand forecast, warns of high price impact

* Coming up: EIA oil data, 10:30 a.m. EDT Wednesday

NEW YORK, March 15 (Reuters) - U.S. crude oil futures fell nearly 4 percent on Tuesday, their biggest one-day percentage loss in nearly five months, as the worsening nuclear crisis in Japan chased investors from riskier assets.

The International Energy Agency warned that OPEC's cushion of spare oil output to calm the market was at its lowest in four years and that sustained high oil prices will damage world economic recovery. [ID:nLDE72EOQ3]

The warning came in a report in which the IEA trimmed its forecast for 2011 oil demand growth. Its latest outlook of 1.44 million bpd was down marginally from last month, pressuring crude prices.

The Federal Reserve said the U.S. economic recovery was gaining traction and inflation pressure from high energy costs should be short-lived. [ID:nN15230117] Oil prices remained lower after the statement, issued after a one-day meeting of Fed policymakers.

In post-settlement trading, crude futures were little changed after data from the American Petroleum Institute showed domestic crude stocks rose 91,000 barrels last week, much less than the forecast in a Reuters poll for a 1.3 million barrel increase. [API/S] [EIA/S]

The API said gasoline stocks fell 458,000 barrels and distillates supplies were down 531,000 barrels, lower than the forecasts for declines of 1.8 million barrels and 1.3 million barrels, respectively, in the poll.

FUNDAMENTALS

* On the New York Mercantile Exchange, crude for April delivery CLJ1 settled at $97.18 a barrel, down $4.01, or 3.96 percent, after trading from $96.71 to $101.87.

* The percentage loss was the biggest for front-month NYMEX crude since Oct. 19, when prices fell 4.32 percent.

* In London, ICE April Brent crude oil futures LCOc1 settled more than 4 percent lower, the biggest single-day percentage drop for front-month Brent in more than 13 months.

* Brent's premium to the U.S. benchmark West Texas Intermediate crude narrowed to $11.34 at the close, from $12.48 on Monday.CL-LCO1=R

* NYMEX April RBOB RBJ1 ended down 15.74 cents or 5.32 percent at $2.8029 a gallon, the lowest close since Feb. 22's $2.7924. It posted the biggest one-day percentage loss since Sept. 1, 2009, when prices fell 10.26 percent.

* NYMEX April heating oil finished down 11 cents or 3.59 percent at $2.9538 a gallon, the lowest since Feb. 28's close at $2.9258. The percentage loss as the biggest for a day since Oct. 19, when prices fell 3.81 percent.

* Japan raced to avert catastrophe after an explosion at a quake-crippled nuclear power plant sent radiation wafting into Tokyo, prompting some to flee the capital. [ID:nL3E7EF311]

* Muammar Gaddafi's forces seized a strategic town in eastern Libya, opening the way to the rebel stronghold of Benghazi while world powers failed to agree to push for a no-fly zone. [ID:nLDE72E00R]

* The Obama administration put Libya's foreign minister on a blacklist and sought ways to tap into some of the billions of dollars of seized Libyan assets to aid an embattled Libyan opposition. [ID:nN159941]

* Bahrain's king declared martial law as his government struggled to quell an uprising by the island's Shi'ite Muslim majority that has drawn in troops from fellow Sunni-ruled neighbor Saudi Arabia. [ID:nLDE72E02N]

MARKETS NEWS

* The yen rose against the dollar as fears of a nuclear catastrophe in Japan sparked a sell-off in global stocks and commodities. [.N]

* U.S. stocks ended down 1 percent but far from session lows after the upbeat Federal Reserve statement aboout the economy and on growing sentiment that Japane's nuclear crisis would depress share prices only temporarily. [.N]

* U.S. gold futures fell as fear of a nuclear disaster in Japan hit financial markets, spurring a flight to cash. [GOL/]

* Copper fell, but trimmed losses late after the Fed's statement. [MET/L] [ID:nLDE71O0F1]

UPCOMING DATA/EVENTS

* U.S. Energy Information Administration's weekly petroleum stocks data, 10:30 a.m. EDT (1430 GMT) Wednesday.

* U.S. producer prices and housing starts data, both for February, 8:30 a.m. EDT, Wednesday.

    SETTLE     NET    PCT     LOW    HIGH  CURRENT  DAY AGO

              CHNG   CHNG                      VOL      VOL
CLc1    97.18   -4.01  -4.0%   96.71  101.87  363,743  289,434
CLc2    97.98   -4.21  -4.1%   97.70  102.79  199,043  121,915
LCOc1  108.52   -5.15  -4.5%  107.88  113.82   97,985  125,650
RBc1   2.8029 -0.1574  -5.3%  2.7768  2.9647   43,754   39,795
RBc2   2.8067 -0.1573  -5.3%  2.7820  2.9635   34,572   25,890
HOc1   2.9538 -0.1100  -3.6%  2.9160    3.06   55,006   56,125
HOc2   2.9608 -0.1101  -3.6%  2.9254  3.0674   31,242   31,276
TOTAL MARKET            VOLUME                 OPEN  INTEREST

          CURRENT    Mar 14   30D AVG     Mar 14  NET CHNG
CRUDE        803,435   565,955   898,194  1,594,210    21,518
RBOB         116,428    94,872   114,098    273,781       278
HO           143,137   154,160   131,256    307,677     3,547
 (Reporting by Gene Ramos and Robert Gibbons; Editing by David
Gregorio)

(Source: http://www.reuters.com/article/2011/03/15/markets-energy-nymex-idUSN1527958020110315)