Oil prices are displayed at a gas station in Seoul, Sunday. Yonhap

Korea's customs agency said Tuesday it has simplified regulations to allow U.S. crude routed through third countries to remain eligible for benefits under the bilateral free trade agreement (FTA), in line with efforts to stabilize the supply amid tensions in the Middle East.

The Korea Customs Service said the new rule, effective Tuesday, will ease procedures for importers to receive benefits under the bilateral FTA for U.S. crude imported to Korea after being transshipped through third countries.

Previously, if crude oil was imported and additionally shipped through a third country, such as Mexico, it was not immediately eligible for preferential treatment under the FTA.

"We decided to proactively ease complicated procedures, under which importers were required to submit documents from transit countries to qualify for FTA benefits," the customs agency said.