Left-wing candidate Michelle Bachelet has been elected Chilean president for a second time, defeating her run-off rival by a wide margin, BBC News said.

With nearly 90% of the vote counted, Ms Bachelet had 62% to 38% for Evelyn Matthei, a former minister from the ruling centre-right coalition.

Bachelet first served as president in 2006-10, after which she was obliged by electoral laws to stand down.

She narrowly missed out on outright victory in the first round last month.

"I am happy with the result and victory and I shall be a president for everyone in Chile," Bachelet, 62, said as she received a congratulatory telephone call from outgoing President Sebastian Pinera, according to Reuters.

At a speech to supporters, she said: "I am proud to be your president-elect today. I am proud of the country we've built but I am even more proud of the country we will build."

Bachelet is now set to become the first leader in Chile to serve two terms since the military rule of Gen Augusto Pinochet in 1973 to 1990.

Upon hearing the news, her supporters have been celebrating on the streets by waving flags and sounding car horns in the capital Santiago.

"It is clear at this point. She won. And we congratulate her. Later on, I will go speak with her personally," Ms Matthei, 60, told reporters.

Official results of Sunday, Dec 15 run-off are expected soon. Turnout appears to have been lower than expected.