SANTIAGO - Preliminary results from Chile's Electoral Service (Servel) on Sunday showed that leftist candidate Jeannette Jara and Republican contender Jose Antonio Kast will advance to a Dec 14 runoff, as neither secured more than 50 percent of the vote.

According to Servel, as of 9 pm local time (2400 GMT), with 77.79 percent of ballots counted in Sunday's first round, Jara led with 26.69 percent of the vote, followed by Kast with 24.15 percent.

Under Chilean law, the two frontrunners will go to a runoff if no one obtains over half of the votes in the first round of the election.

Chilean President Gabriel Boric congratulated Jara and Kast in a televised speech.

"(On) Dec 14, Chile will once again elect the president of our country, who will direct the destinies of our homeland for the next four years," Boric said.

"I am confident that dialogue, respect and affection for Chile will come first over any difference," he added.