Ahn Cheol-soo’s decision ends months of speculation on whether he would run in December elections and adds a new complexity to the race.
The founder of Seoul-based antivirus maker AhnLab told reporters Wednesday that he’s running because of public calls to reform politics.
Ahn has long been neck-and-neck in a hypothetical two-way matchup against conservative ruling party candidate Park Geun-hye in opinion surveys. But he has been vague until now about his ambitions.
Park is the daughter of late dictator Park Chung-hee.
Liberal opposition candidate Moon Jae-in is running third in polls behind Park and Ahn. Moon has said he’ll seek to win Ahn’s support so they can muster liberal votes against Park.