FACTBOX: South Korea presidential election at a glance

(Reuters) - South Koreans elect a new president on Wednesday to serve a single five-year term as head of the world's 13th largest economy.

Here is a glance at the race:

MAIN CANDIDATES:

Lee Myung-bak, who turns 66 on election day, is the front-runner and candidate of the conservative opposition Grand National Party (GNP). He is a former top executive of the Hyundai Group and was a popular mayor of Seoul.

Chung Dong-young, 54, is a distant second. He is the candidate of the left-leaning, ruling United New Democratic Party who was once a TV news presenter and served in the current government as the cabinet minister responsible for North Korea affairs.

Lee Hoi-chang, 72, is third. He is a staunch conservative who ran and lost twice as the GNP's candidate in 1997 and 2002. He is running as an independent.

POLL NUMBERS

Support rate from daily newspaper Chosun Ilbo poll published on December 13, the last allowed by law before the election: Lee Myung-bak 45.4 percent, Chung 17.5 percent, Lee Hoi-chang 13.6 percent.

Top issues for voters from national daily Hankyoreh poll published on December 3: Economic management 43.5 percent, employment 17.3 percent, social welfare 14.3 percent, education 11.5 percent, real estate prices 6.8 percent, North Korea policy 3.2 percent.

MAIN POLICIES:

Lee Myung-bak wants to cut regulations on business, tempt more foreign investment and clamp down on illegal strikes. He has pledged to take a tough line on North Korea and tie aid to progress it makes on ending its nuclear arms program.

Chung wants to increase welfare spending and use the government to help make industries such as aerospace and robotics become drivers of the economy. He advocates a steady flow of aid to North Korea and expanding joint cooperation projects.

Lee Hoi-chang promises to have the toughest line on North Korea. He wants Pyongyang to return several hundred South Koreans it has kidnapped.

ELECTION DAY OUTLINE:

Voting ends at 6 p.m. local time (4 a.m. EST). Voting age is 19 and there are 37.67 million voters.

Television networks usually report their projected winner based on exit polling shortly after voting ends. The National Election Commission said it expects to have most of the results released by about 10 p.m. (8 a.m. EST).

The new president takes office on February 25.

(Reporting by Jon Herskovitz and Jessica Kim; Editing by Grant McCool)