Ahn Cheol-soo, a popular South Korean entrepreneur-turned-professor, broke his long silence Wednesday to officially declare his presidential bid. "People have expressed their aspirations for political changes through me," the mild-mannered 50-year-old Seoul National University professor told a throng of reporters during a nationally televised press conference."I will run for president."

The announcement ended months of frenzied media speculation over the future political trajectory of Ahn, long considered one of the strongest potential presidential hopefuls looking to replace President Lee Myung-bak when his five-year term ends early next year.

Opinion polls have suggested Ahn, the founder of the anti-virus software firm AhnLab, is the only one who can challenge the matchless presidential candidate of the conservative ruling Saenuri Party, Park Geun-hye.

Moon Jae-in, nominated last Sunday as the presidential candidate of the center-left main opposition Democratic United Party, has even publicly proposed a coalition government with Ahn.

An untested political novice, Ahn emerged as an unlikely kingmaker during the closely watched Seoul mayoral election last year. He is widely expected to play a similar role for the December poll by endorsing Moon later in the campaign.

Despite a barrage of recent attacks from conservatives who once courted Ahn to join their camp, the software mogul remains popular among the moderates and independents disenchanted with the political establishment.

The presidential election is slated for Dec. 19, with Lee constitutionally barred from seeking re-election.