* FTSEurofirst 300 up 0.3 pct after Monday's slump
* Greek shares fall again on election uncertainty
* BMW rallies after deliveries update
By Francesco Canepa
LONDON, Dec 10 (Reuters) - European equity indexes staged a modest rebound on Wednesday, led by German stocks after a strong update from BMW, although worries about Greece capped sentiment.
Greece's main stock index fell 3 percent at 0914 GMT, extending Monday's losses on uncertainty surrounding a parliamentary vote to elect a new president later this month.
If Prime Minister Antonis Samaras fails to secure victory for his presidential candidate, snap national elections could be called that the leftist Syriza party - a fierce opponent of Greece's bailout deal with the European Union and IMF - would likely win.
A 15 percent rally in European shares since mid-October, fuelled by expectations that the European Central Bank would start buying sovereign bonds next year, ran into the sand this week after the Greek government called the presidential elections late on Monday.
Traders worry uncertainty in Greece could cause the ECB to postpone any decision on bond purchases, known in the market as quantitative easing, or QE.
"If there's complete indecision in Greece, the ECB is unlikely to do something in January, which would take that (support) away from the market," Mike Reuter, a broker at Tradition, said.
"I'm bearish overall but the QE pushes the market higher so nothing get in its way, I'll have to be bullish in the year-end."
Elsewhere, BMW Group rose 1.1 percent after saying deliveries of BMW, Mini and Rolls-Royce cars rose 7.6 percent in November to 188,342 thanks to a continued strong demand in China and a 20 percent rise of its BMW and Mini sales in the UK.
Germany's Dax index was up 0.7 percent, outperforming all major European indexes and the FTSEurofirst 300 index of top regional shares, which was up 0.3 percent at 1,367.28 points. It had fallen 2.3 percent on the previous day.
Among smaller stocks, Britain's Ashtead rallied 6.7 percent after raising its full-year earnings guidance and posting a 33 percent rise in first-half profit.
Europe bourses in 2014: link.reuters.com/pap87v
Asset performance in 2014: link.reuters.com/gap87v
Today's European research round-up (Reporting By Francesco Canepa; Editing by Andrew Heavens)