By Ju-min Park and Se Young Lee
SEOUL (Reuters) - Liberal politician Moon Jae-in won South Korea's presidential election on Tuesday, an exit poll showed, an expected victory that would end nearly a decade of conservative rule and bring a more conciliatory approach toward North Korea.
A decisive win for Moon would end months of political turmoil that led to parliament's impeachment of conservative former President Park Geun-hye over an extensive corruption scandal.
The Constitutional Court upheld the impeachment in March, making Park the first democratically elected leader in South Korea to be removed from office and triggering a snap election to choose her successor.
Wearing a dark blue suit and blue tie, Moon was seen shaking hands with supporters and party officials and smiling on his way to a meeting of his Democratic Party after the exit poll results were announced.
"We will need to calmly wait and see as this was just exit polls," he told party members. "But if things go on this way and we win, today’s victory is thanks to sheer desperation of the people who wanted a regime change."
"We will accomplish the two tasks given to us, reform and national unity that the people of this country desire."
The exit poll by South Korea's three biggest broadcasters showed Moon, 64, capturing 41.4 percent of the votes in a field of 13 candidates. Official results were expected in the wee hours of Wednesday morning.
Former prosecutor Hong Joon-pyo was second with 23.3 percent of the votes and centrist candidate Ahn Cheol-soo had 21.1 percent. Definitive official results were expected early on Wednesday. A plurality is enough for victory.
"If exit polls are true, I will accept the results and just be satisfied with the fact that the Liberty Korea Party will be restored," a downbeat-looking Hong told members of his conservative party.
Ahn said he would "humbly accept" the result.
FRACTURED PARLIAMENT
Moon is expected to be sworn in for a five-year term later on Wednesday. He has said he would skip a lavish inauguration ceremony and start work straight away.
He is likely to quickly name a prime minister, who will need parliamentary approval, and the main cabinet positions, including national security and finance ministers, which do not need parliamentary confirmation.
Moon, who narrowly lost to Park in the last presidential election, in 2012, favors dialogue with North Korea to ease rising tension over its accelerating nuclear and missile program. He also wants to reform powerful family-run conglomerates, such as Samsung and Hyundai, and boost fiscal spending to create jobs.
Moon has criticized the two former conservative governments for failing to stop North Korea's weapons development. He advocates a two-track policy of dialogue while maintaining pressure and sanctions to encourage change.
Moon faces working with a fractured parliament where his Democratic Party holds 40 percent of the single-chamber, 299-seat assembly, which will likely mean difficulties and deals to pass bills.
His victory was bolstered by strong support from younger people, according to the exit polls. Many of his supporters participated in big, peaceful weekend rallies over the last few months of 2016 and early this year, demanding Park step down.
Only between 22 percent and 25 percent of people in their 60s and 70s voted for Moon, exit polls showed, underscoring a long-standing generation gap. Many older people are wary of Moon's less confrontational stance on North Korea.
QUESTION OVER U.S. ANTI-MISSILE SYSTEM
Moon, whose campaign promises include a "National Interest First" policy, has struck a chord with people who want the country to stand up to powerful allies and neighbors.
He wrote in a book published in January South Korea should learn to say "no to America".
The former human rights lawyer was a close friend and confidant of late president Roh Moo-hyun, who served from 2003 to 2008 and advocated a "Sunshine Policy" of engaging North Korea through aid and exchanges.
Moon believes better inter-Korean relations is the best way to provide security. But Washington is worried his moderate stance could undercut efforts to increase pressure and sanctions, senior South Korean officials said.
"Things are not right to resume the so-called Sunshine Policy, as the U.S. and China turned more hostile towards North Korea," said Koh Yu-hwan, Dongguk University professor of North Korean studies, who is serving as a foreign policy adviser to Moon.
"Still, Moon is expected to engage in discussions, which could improve North-South relations."
Moon's election could also complicate the deployment of the Terminal High Altitude Area Defence (THAAD) system, which the former government in Seoul and the U.S. military agreed to last year.
Moon has said the decision was made too quickly and the next administration should have the final say on whether to deploy the system.
The election was closely watched by allies and neighbors at a time of high tension over North Korea's accelerating development of weapons since it conducted its fourth nuclear test in January last year. It conducted a fifth test in September and is believed to be preparing for another.
Moon said in a YouTube live stream on Tuesday South Korea should take on a more active diplomatic role to curb North Korea's nuclear threat and not watch idly as the United States and China talk to each other.
(Reporting by Ju-min Park, Se Young Lee, Cynthia Kim in SEOUL, Writing by Soyoung Kim and Jack Kim,; Editing by Robert Birsel and Bill Tarrant)