* Downward trend outweighs tensions in Korean peninsula
* Technicals show oil in narrow range [
]* Coming Up: API oil inventory data; 2130 GMT (Adds Korean tension, analyst's quote, updates prices) )
By Florence Tan
SINGAPORE, Nov 23 (Reuters) - Oil fell to near $81 on Tuesday, as the dollar gained against the euro on fears that Ireland's debt crisis may spread in the euro zone, resuming its downward trend after a brief upwards blip on news of tension running high on the Korean peninsula.
North Korea fired dozens of artillery shells at a South Korean island, setting buildings on fire and provoking a return of fire by the South, Seoul's military and media reports said. [
]U.S. crude for January <CLc1> shed 67 cents to $81.07 a barrel by 0744 GMT, after having dropped 71 cents on Monday. ICE Brent <LCOc1> was down 66 cents to $83.30 a barrel.
The market tended to heavily discount incidents such as Tuesday's Korean exchange, one analyst said.
"People would buy the dollar and that would have an effect on crude's ability to climb higher," said Jonathan Barratt, managing director of Sydney-based Commodity Broking Services.
News of the exchange of fire sent U.S. 10-year Treasury futures <TYc1> rising and the Japanese yen falling. The dollar index , which measures the greenback against a basket of currencies, gained 0.31 percent.
The euro earlier fell to as low as $1.3548, coming under renewed pressure as political uncertainty in Ireland and worries about other heavily-indebted members of the 16-nation bloc snuffed out initial optimism over a bailout plan for Dublin.
"Further oil market volatility cannot be excluded as Irish domestic political developments may yet slow the negotiation of the aid package with the EU/IMF, and that attention will at some point shift its focus to other euro zone economies," JPMorgan analysts said in a note.
"Looking forward over the course of the week, there appears to be little macroeconomic news to drive sentiment, apart from the repercussions of the Irish settlement."
Irish Prime Minister Brian Cowen defied mounting pressure to quit on Monday, saying he would stay in office until parliament passed an austerity budget needed to secure the IMF/EU bailout, which could total 80 billion to 90 billion euros, and then call an early election. [
]
DROP IN CRUDE STOCKS
However, hopes of a drawdown in U.S. crude stocks in the week to Nov 19, reflecting better demand at the world's top energy consumer, may support prices.
Data from the United States is expected to show a third week of decline for crude inventories in the week to Nov. 19 following a surprise heavy drawdown in the previous week, a Reuters poll showed on Monday.
"Seasonally demand (in the U.S.) should be improving in this quarter of the year. Inventories are coming off, especially for distillates," said Serene Lim, a Singapore-based oil analyst at ANZ.
Traders are also watching the impact from a disruption of Shell's crude production in Nigeria.
Nigerian output of Bonny Light crude has fallen by about 100,000 barrels per day (bpd) to between 210,000 and 220,000 bpd after a damaged pipeline led Shell to declare a force majeure on exports on Friday. [
]The market is also keeping an eye on the political situation in Saudi Arabia as the country's aging King Abdullah arrived in the United States for medical treatment on Monday, while a frail Crown Prince Sultan hurriedly returned from abroad to govern the world's largest oil exporter. [
]
(Editing by Clarence Fernandez)