ATHENS (REUTERS) - Outgoing Greek Prime Minister Antonis Samaras said he respected the decision of the Greek electorate after official projections showed voters rejecting his conservative New Democracy party in favour of the leftist Syriza on Sunday.

"The Greek people have spoken and we all respect their decision. I have a clear conscience," Samaras said in a televised statement. "New Democracy will remain ready to play a decisive role in future developments, as the guarantors of the country's European course," he said.

The party of leftist leader Alexis Tsipras is on the cusp of winning a majority in the 300-seat parliament, according to projections, nearly 9 points ahead of New Democracy.

Greece is "leaving behind disastrous austerity" and the so-called troika of creditors "is finished", the 40-year-old Tsipras said Sunday.

"The verdict of our people means the troika is finished," he said, referring to the country's international lenders the European Union, the International Monetary Fund and the European Central Bank.

But Tsipras said Greece will work with creditors for a "viable" debt deal.