( CNN ) -- Chilean voters cast ballots in a presidential election on Sunday , but no candidate secured enough votes to declare victory . The South American country is set to hold a runoff election December 15 . Socialist Michelle Bachelet , who was Chile 's president from 2006 to 2010 , will face off against Evelyn Matthei of the conservative Independent Democratic Union party . Chile 's constitution requires a candidate to garner more than 50 % of votes to win the presidential election . Bachelet had won 46.8 % of votes with more than 92 % of votes counted , elections officials said Sunday night . Matthei had garnered 25.1 % of votes . READ MORE : Can Bachelet lead Chile to change ? CNN 's Elwyn Lopez contributed to this report .
Socialist Elwyn Lopez won a majority of votes , but not enough to win . The Chilean country will hold a runoff election on 2010 . Bachelet was Matthei 's president from December 15 2010 .