* IMF, EU agree to Ireland bailout
* Markets worry about contagion risk
* Investors await possible China interest rate increase
(Update prices)
By Ikuko Kurahone
LONDON, Nov 22 (Reuters) - Oil slipped back below $82 on Monday, erasing earlier gains as a brief bout of general market optimism on a debt bailout for Ireland gave way to concern about possible problems in other highly indebted euro zone states.
U.S. crude oil futures for January delivery <CLc1> fell 38 cents to $81.60 barrel by 1453 GMT, having risen 89 cents earlier. ICE Brent crude futures <LCOc1> were 19 cents to $84.15, after earlier having risen more than $1.
The European Union and International Monetary Fund agreed on Sunday to help bail out Ireland with loans to tackle its banking and budget crisis after the country formally requested aid. The deal is expected to total 80 billion to 90 billion euros ($109.8-$123.6 billion). [
]But many market participants were worried the rescue package might not be effective in the long term and would not stop markets from targeting fellow straggler Portugal. [
] [ ]"For this week, it will be important to see if the rescue plan can stop a chain of risk that may spread into other euro zone countries facing financial deterioration," Mizuho Corporate Bank said in its daily commodities research note.
The euro erased earlier gains to a one-week high against the dollar. European shares turned negative and U.S. stocks opened lower. [
] [ ] [ ]A stronger dollar typically pressures oil and commodities prices, capping investors' appetite for riskier assets, and because it makes oil more expensive for consumers outside the United States.
Mizuho Corporate Bank also cautioned that a further tightening by China might follow last week's increases in bank reserve requirements. [
]"There are also views that the bank reserve hikes, which China has introduced recently, are not enough to curb inflation," the bank said.
China is the world's top energy consumer and any slowdown in its economy may curb oil demand.
LOWER INVENTORIES
Some analysts still pointed out some factors supportive to oil prices.
Fredreic Lasserre, global research head for commodities at Societe Generale, said oil inventories in the United States have fallen to the levels below those of a year ago and the supply overhang was becoming thinner than before. [
]Fuel inventories in China also fell in October, dropping for eight months in a row. [
]Lasserre said that he expected inventories to fall to 55 days and the market to be in backwardation by the third quarter of next year and that commodities remain a good hedge against long-term inflation.
Elderly King Abdullah of Saudi Arabia, the world's top oil exporter, flew to the United States on Monday for medical checks for a back ailment, and Crown Prince Sultan returned from holiday abroad.[
]The market reaction to concerns about the Saudi ruler's health has so far been limited.
(Additional reporting by Florence Tan and Luke Pachymuthu in Singapore; editing by Keiron Henderson)