The Korea Composite Stock Price Index (KOSPI) ended up 0.51 percent at 2,013.66 points.

"As the Japan nuclear fears eased a bit, investors' focus has shifted to earnings ahead of results season next month," said Bae Sung-young, a market analyst at Hyundai Securities.

"We are seeing clear sectoral differentiation today, with automakers, refiners, and chemical firms outperforming as their earnings are seen strong," Bae added.

Uncertainties including the turmoil in Libya continued to weigh on investor sentiment, and the main index will face resistance near its 60-day moving average of around 2,030 points, said Samsung Securities analyst Kwak Joong-bo.

Foreign investors were buyers of a net 235.9 billion won ($209.7 million) worth of stocks, picking up shares for a fifth consecutive session.

Automakers rallied, with Hyundai Motor ending up 4.4 percent, rising for a third straight session. Kia Motors surged 3.6 percent.

Refiners advanced, helped by continued strength in oil prices. Shares in SK Innovation, the country's No.1 crude oil refiner, climbed 4.2 percent and S-Oil advanced 2.5 percent.

Chemical firms likewise rose amid positive earnings expectations.

LG Chem gained 2.2 percent and Honam Petrochemical surged 5.3 percent.

Shipbuilders gained amid order hopes after the Korea Exchange asked Samsung Heavy Industries to clarify a media report it had won a large container ship order. Samsung said it would respond to the request by the end of the day.

Shares in Samsung Heavy Industries rose 3.4 percent and Daewoo Shipbuilding & Marine Engineering climbed 2.8 percent.

But technology issues eased. Shares in Samsung Electronics, the world's No.1 memory chip maker, lost 1.7 percent and LG Display slipped 1.6 percent.

The KOSPI 200 June futures index finished up 1.40 points at 267.05. The KOSPI 200 spot index rose 1.16 points to 266.05.

The junior Kosdaq market ended up 0.25 percent at 507.80.