* U.S. jobless claims fall, factory activity rises
* Spain debt worries, euro zone contagion fears weigh
* Markets re-evaluate fall in U.S. crude oil inventories (Recasts, adds new by-line, changes dateline previously LONDON)
By Gene Ramos
NEW YORK, Dec 16 (Reuters) - Oil prices slipped on Thursday but held above $88 a barrel, amid signs of pre-yearend book squaring and as the dollar reversed to the upside after a slew of positive U.S. economic data.
Investors also reassessed Wednesday's data showing a sharp crude stock inventory drawdown, noting it was tax-driven and a one-off event that will give way to higher supplies in the coming weeks.
U.S. crude for January delivery <CLc1> dropped 30 cents to $88:32 a barrel by 12:50 p.m. EST (1750 GMT). The contract is expiring on Monday, which added pressure.
U.S. oil prices hit a two-year high of $90.76 early last week. Since then they have fallen toward $88, revealing a pattern of long liquidation ahead of year end, analysts said.
U.S. heating oil futures, usually the season's price leader, edged slightly higher. But buying was tempered by forecasts for moderating temperatures in much of the United States after a deep freeze in the East Coast this week.
"Some degree of December book squaring ahead of the year end may be adding a flow of profit taking to the mix, but traders might also be wary of the price performance itself after the market failed to translate the larger-than-expected 9.9 million barrel drop in DOE crude stocks for last week into more of a rally," said Tim Evans, energy analyst at Citi Futures Perspective in New York.
In London, ICE Brent for January <LCOc1>, which expires Thursday, fell 8 cents to $92.12 a barrel.
DOLLAR SHIFTD HIGHER ON U.S. DATA
The dollar recovered earlier losses on the day's encouraging U.S. economic data as bond yields rose, helping pressure oil prices. [
]U.S. economic reports showed jobless insurance claims fell for a second week, factory activity in the Mid-Atlantic region surged this month at its quickest pace in more than 5-1/2 years and housing starts rose in November. [
]A stronger dollar can often pull down dollar-denominated oil prices as it makes fuel more expensive for holders of other currencies.
The euro rose early as a European Union summit started to discuss the region's debt crisis, but fell back on persistent worries about fiscal stability. Investors were cautious a day after ratings agency Moody's warned that it might downgrade Spain's credit rating.
The U.S. Commodity Futures Trading Commission, which regulates the nation's commodities markets, on Thursday set out steps to carry out position limits, seen as an aggressive move to prevent speculators from distorting commodity markets. But the CFTC relented on several measures that were opposed by Wall Street banks and big traders. [
]There was no impact on oil prices when the agency released its proposals for a 60-day public comment period. (Additional reporting by Robert Gibbons in New York; Una Galani in London; Rebakah Kebede in Perth, Australia; Editing by David Gregorio)