SEOUL, May 9 (Reuters) - Liberal politician Moon Jae-in won South Korea's presidential election on Tuesday, exit polls 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 by Moon, with more than 40 percent of votes in a field of 13 candidates, would end months of political turmoil stemming from a parliamentary vote in December to impeach former President Park Geun-hye over an extensive corruption scandal.
The Constitutional Court upheld her impeachment in March, making her the first democratically elected leader to be removed from office and triggering a snap election to choose her successor.
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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."
Moon, 64, was beating conservative challenger, former prosecutor Hong Joon-pyo, by 41.4 percent to 23.3 percent of the votes, exit polls conducted jointly by three network television stations showed.
A Gallup Korea poll last week showed Moon had 38 percent support in a field of 13 candidates.
Moon is expected to be sworn in on Wednesday after the National Election Commision releases the official result. 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 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 dialog 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 dialog while maintaining pressure and sanctions to encourage change.
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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.
"He has to pursue cooperation with other liberal and centrist parties, since the Democratic Party does not have the majority," said Kim Man-heum, head of the Korea Academy of Politics and Leadership.
"Moon has been criticized for running his own 'clique', so in order to get over that negative image, he'll seek cooperation to avoid rifts and conflicts," Kim said.
His victory was bolstered by strong support from younger people, the majority of whom voted for him, 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.
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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."
A 64-year-old former human rights lawyer, Moon was a close friend and confidant of late president Roh Moo-hyun, who served from 2003 to 2008 and advocated the so-called "Sunshine Policy" of trying to engage North Korea through aid and exchanges.
Moon believes better inter-Korean relations is the best way to provide security on the Korean peninsula. But Washington is worried his moderate stance could undercut efforts to increase pressure and sanctions, senior South Korean officials said.
His 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.
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Moon has said the decision was made hastily 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 ready 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.