* Warmer northern hemisphere weather cuts fuel use outlook
* Oil falls $5 this week on assumptions for economy, demand
* CFTC proposals unlikely to affect most market participants
(Updates prices, detail)
By Christopher Johnson
LONDON, Jan 15 (Reuters) - Oil slipped to around $79 per barrel on Friday and was set for its first weekly drop in more than a month on disappointing economic data and expectations for reduced heating demand in the United States.
A cold snap in many parts of the northern hemisphere helped push prices above $80 in early January but warmer weather this week has reduced forecasts for fuel consumption, particularly in the world's biggest oil consumer, the United States.
U.S. retail sales figures on Thursday also put a dampener on the market as Commerce Department data showed a decline in December for the first time in three months. [
]U.S. crude oil futures for February delivery <CLc1> slid 48 cents to $78.91 a barrel by 1043 GMT.
Oil, which has fallen every day this week, has shed about $5 from a 15-month intraday high of $83.95 on Monday, and touched a 2010 low of $78.37 on Wednesday.
The new front-month March contract for London Brent crude <LCOc1> slid 67 cents to $77.90.
"The market is responding to rather disappointing figures from the United States, which suggest oil demand will be weaker than expected. U.S. oil data this week points to softer fundamentals than don't justify prices around $80 per barrel," said Carsten Fritsch, analyst at Commerzbank.
"PSYCHOLOGICAL FACTOR"
"Colder weather was used as an argument to buy oil, but it was only a psychological factor and now that has been removed."
Edward Meir, senior commodity analyst at brokers MF Global, said his team "remains negative on the energy markets".
He forecast "a gradual retreat towards the mid to high $70s into early next week as the excessive rally generated on account of colder weather is rolled back".
Crude and fuel inventories in the United States rose last week despite unusually cold weather. Temperatures are now forecast to exceed the seasonal norm, suppressing consumption.
U.S. demand for distillates, a fuel category which includes heating oil, was 4 percent below year-earlier levels in the four weeks ended Jan. 8, a government report showed on Wednesday.
The International Energy Agency kept its forecast for the increase in oil demand this year almost unchanged in its monthly oil market report, predicting global oil consumption would rise by 1.4 million barrels per day (bpd) from 2009. [
]World oil demand will be around 86.3 million bpd this year, still lower than the 86.5 million bpd used in 2007. Consumption has fallen for the last two years due to the global economic slowdown triggered in 2007.
Oil prices edged up briefly on Thursday after U.S. regulators announced proposals to cap the size of positions dealers can hold, aiming to limit speculation. [
]The recommendations by the U.S. Commodity Futures Trading Commission (CFTC) will apply to the four most-traded energy contracts on the two major exchanges, NYMEX and ICE.
Analysts said the Commission had produced a set of largely workable proposals that would not inconvenience regular market users. The CFTC said the measures would affect only the 10 biggest position holders if implemented immediately.
It remains to be seen if the limits are enough to satisfy Congress members who have clamoured for regulatory action since oil prices jumped to a record above $147 in July 2008.
Markets awaited the release of further U.S. economic indicators later on Friday, including industrial production. [
] (Additional reporting by Alejandro Barbajosa in Singapore; editing by Keiron Henderson)