Bark's candidacy was submitted three days before nominations close and as Pascal Lamy, the global trade body's current director general, prepares to step down on Aug. 31, 2013.
Although Lamy has said his successor should be chosen on the basis of competence alone, some trade diplomats say it is the turn of a developing country to hold the job.
Bark is the second candidate from a rich country and the third from the Asia-Pacific to apply.
So far, all but one of the candidates are serving or former trade ministers and several, like Bark, have U.S. doctoral degrees in economics and strong academic credentials.
Apart from South Korea, countries that have nominated candidates include Mexico, Indonesia, Costa Rica, Ghana, Jordan, Kenya and New Zealand. More could be put forward before the deadline of midnight on Dec. 31.
The candidates will present their case for becoming the sixth head of the WTO at a meeting at its Geneva headquarters on Jan. 29, part of a three-month campaigning period after which the field will be gradually whittled down.
The candidate with the least support among the WTO's 157 members will be asked to withdraw until a winner emerges, something expected to happen by the end of May.
Bark may be seen as the candidate most closely associated with regional free trade agreements (FTAs), as South Korea has been eager to negotiate such deals with the United States and China among others.
Although every member of the WTO is involved in such free trade deals, critics say the rush to broker regional agreements could create a fragmented trading world and undermine the WTO as a system for unifying and equalising trade rules.
In pursuing FTAs, South Korea has pointed to the benefits to its own economy rather than to the global trading system.
"By penetrating these major markets of global economic activities through separate and independent FTAs, Korea endeavors to place itself at the center of global economic traffic," Bark told the American Chamber of Commerce in Seoul in March this year.
"Korea's strategy of creating a global FTA hub is proving to be a success," he said.
But Bark also said that the emergence of regional blocs must revitalise the global WTO system and should be recognised as "building blocks, rather than obstacles". During the selection process, he may be pressed to flesh out his ideas for making that happen. (Reuters)