BERLIN (Reuters) - Chancellor Angela Merkel's center-right coalition held a narrow lead over the combined left-leaning opposition parties, an opinion poll showed on Thursday, three days before a national election.

The Politbarometer survey by Forschungsgruppe Wahlen gave Merkel's conservatives 40 percent, unchanged from the pollster's last survey on Sept 13. Their current coalition partner, the Free Democrats (FDP), were on 5.5 percent, down 0.5 points.

The main opposition Social Democrats had 27 percent, up one point, their Green allies were on 9 percent, down two points, and the hardline Left had 8.5 percent, up 0.5 points.

A new Euroskeptical party, the Alternative fuer Deutschland, which wants to force weaker southern European countries out of the euro zone, had 4 percent, unchanged from the last FGW poll and below the 5 percent threshold to enter parliament.

(Reporting by Gareth Jones)