(Yonhap) -- South Korea's presidential contest is in a dead heat, with a survey released Saturday showing ruling party candidate Park Geun-hye tied in hypothetical two-way races with her two main rivals, opposition candidate Moon Jae-in and independent candidate Ahn Cheol-soo.

   Park and Moon tied at 47 percent of support in a supposed two-way race, while she also tied with Ahn at 47 percent of support in a two-way contest, according to the Gallup Korea survey of 1,248 voters across the nation conducted on Oct. 4-5.

   The poll had a margin of error of plus or minus 2.8 percentage points.

   In a three-way contest, Park was way ahead of the two others with 40 percent, followed by Ahn with 26 percent and Moon with 24 percent, the survey showed.

   Election experts say Ahn and Moon are expected to ultimately join hands to select one of them as a unified candidate as they see little chance of beating Park if both remain in the race and split the liberal vote.

   Moon was more favored than Ahn as a unified candidate. Asked who they favor as a single candidate, 50 percent of the respondents picked Moon while 36 percent selected Ahn, the survey showed.

   The presidential vote is set for Dec. 19. By law, incumbent President Lee Myung-bak cannot seek a second term.