(Recasts with official prices, China's policy meeting readout)

By Polina Devitt

LONDON, Dec 12 (Reuters) - Copper prices fell on

Thursday due to a lack of clarity on the size of the economic

stimulus promised by China's key policy meeting and expectations

of oversupply in the global copper market next year.

Three-month copper on the London Metal Exchange (LME)

lost 0.4% at $9,152 per metric ton in official

open-outcry trading.

The metal, used in power and construction, is up 6.5% so far

this year partly due to the efforts of China, the world's

second-largest economy and top metals consumer, to put a stop to

a prolonged downturn in its property market.

China pledged on Thursday to stabilise its housing market,

increase the budget deficit, issue more debt and loosen monetary

policy to maintain a stable economic growth rate as it gears up

for more trade tensions with the United States as Donald Trump

returns to the White House.

The readout of an annual agenda-setting meeting, however,

did not disclose the size of the stimulus measures or next

year's growth targets.

There are signs of some improvement in sentiment towards

China's property sector, but copper is yet to find any support

from this.

"We are seeing more and more stimulus measures coming from

China, which is good news for the economy," said Dan Smith at

Amalgamated Metal Trading (AMT).

"There is obviously a long way to go, but it is moving in

the right direction: the property market is starting to improve

in terms of sales," Smith said, referring to November's

improvement in property sales in terms of floor space.

Meanwhile, global refined copper market is facing a surplus

of 491,000 tons in 2025, the largest since 2020, making

dollar-priced copper more vulnerable to the U.S. currency

strength, analysts at BNP Paribas said in a note.

BNP Paribas downgraded its forecast for the 2025 average

copper price by 5% to $9,020.

LME aluminium rose 0.1% to $2,604 in official

activity, zinc fell 1.0% to $3,095, lead lost

1.1% to $2,021, tin slipped 0.7% to $29,750, while

nickel added 2.1% to $16,190.