UPDATE 3-Oil prices slip as market awaits output deal

* Formal OPEC+ meeting delayed to Thurs from Tues -sources
* Market betting on extension of cuts through Q1 -analyst
* U.S. crude stocks rose 4.1 million barrels last week -API
* Coming up: EIA inventory data at 1530 GMT

(Updates prices, adds comment)
By Noah Browning
LONDON, Dec 2 (Reuters) - Oil prices slipped on Wednesday as
the market awaited a pact from producers on output, although
Britain's approval of a COVID-19 vaccine gave hopes for a demand
recovery a boost.
Prices were hit by a surprise build in oil inventories in
the United States and as OPEC and its allies created uncertainty
with a two-day delay to a formal meeting to decide whether to
increase production in January.
Brent crude oil futures LCOc1 were down 13 cents, or 0.3%,
at $47.29 a barrel by 1203 GMT, while West Texas Intermediate
crude CLc1 was down 21 cents, or 0.5%, at $44.34.
Industry data from the American Petroleum Institute showed
U.S. crude inventories rose by 4.1 million barrels last week,
compared with analysts' expectations in a Reuters poll for a
draw of 2.4 million barrels. "Traders would not take huge gambles today, as they are
waiting for the final verdict of Thursday's OPEC+ meeting", said
Rystad Energy's head of oil markets, Bjornar Tonhaugen.
"When stakes are so high, it is dangerous to move prices
much ahead".
The Organization of the Petroleum Exporting Countries
(OPEC), Russia and other allies, a group known as OPEC+,
postponed talks on next year's oil output policy to Thursday
from Tuesday, according to sources. The group this year imposed production cuts of 7.7 million
barrels per day (bpd) as the coronavirus pandemic hit fuel
demand.
It had been widely expected to roll those reductions over
into January-March 2021 amid spikes in COVID-19 cases.
But the United Arab Emirates (UAE) said this week that even
though it could support a rollover, it would struggle to
continue with the same deep output reductions into 2021.

Britain on Wednesday became the first western country to
approve a COVID-19 vaccine, jumping ahead of the United States
and the European Union in what may be a first step toward a
return to normal life and boost oil consumption.