* FTSEurofirst 300 down 1.2 pct
* Miners fall as U.S. data puts focus on taper
* Airlines down on bird flu concerns
By Tricia Wright
LONDON, Dec 3 (Reuters) - European stocks fell on Tuesday, suffering their biggest falls since August after recent robust U.S. data raised concern that the Federal Reserve will cut its equity-friendly stimulus sooner rather than later.
The FTSEurofirst 300 was down 1.2 percent at 1,285.79 points by 1556 GMT in a broad-based sell-off, trading at its lowest levels in nearly three weeks. This left it 2.4 percent shy of a 5-1/2 year high of 1,316.42 hit early November.
The sell-off represented a wipeout of about 50 billion euros ($67.78 billion) in market capitalisation for euro zone benchmarks DAX, CAC-40, IBEX and FTSE MIB combined.
Miners fell, tracking metals prices lower, with traders blaming stronger-than-expected U.S. manufacturing and construction spending data on Monday for the weakness.
A robust economy is normally good for equities, but the recent improving outlook could lead to an early reduction in the U.S. Federal Reserve's bond-buying programme, which has supported the rally in equities.
Investors are aware the central bank will start reducing stimulus at some point, but question marks remain about the timetable for doing so. Most expect the announcement in March.
The Fed has said it will begin to scale back its programme when certain economic data releases meet its targets, with Friday's November jobs report expected to provide some clues.
"I think tapering is not going to happen in December; first of all I'm not so sure (Friday's) figure will be so strong," said Philippe Gijsels, head of research at BNP Paribas Fortis Global Markets.
"I would even be willing for people who want to play the short term ... to buy into the figure because I think maybe we will have a rally afterwards."
European airlines came under pressure after the first case of deadly bird flu in Hong Kong fanned concern that the virus is continuing to spread beyond mainland China's borders.
Air France-KLM fell 2.1 percent and Germany's Lufthansa was off 3.6 percent.
There was profit-taking in autos stocks, down 2.1 percent, among the worst-hit sectors. They have risen by around a third in 2013, making them the best performers.
Still, analysts see scope for more gains. JPMorgan is bullish on European autos in 2014 as it expects that a recovery in the European, Chinese and North American car markets will support higher earnings.