South Korean President Lee Myung-bak and Thai Prime Minister Yingluck Shinawatra held preliminary talks on the deal at a summit in Bangkok Saturday, Yonhap News Agency reported.
"Both sides agreed to seek preliminary discussions and a joint study about forging a comprehensive economic partnership agreement (CEPA) in order to strengthen economic links between the two countries," the joint statement said.
A CEPA is the equivalent of a free trade agreement.
After the summit, South Korean Foreign Minister Kim Sung-hwan and his Thai counterpart, Surapong Tovichakchaikul, signed a memorandum of understanding, forming what they called a "strategic partnership" between the two countries.
"I firmly believe the two countries will open up an era of higher level of cooperation," Lee said during a joint news conference with Yingluck. "I take pride in that we were able to move bilateral relations forward and reach agreement in various areas ahead of next year's 55th anniversary of relations."