"The central theme is still on Europe, and although France's bond auction (on Thursday) did not yield disastrous results as some had feared, its negative outlook and possible credit rating downgrade are sources of lingering fear," Kim Soo-young, a market analyst at KB Investment & Securities, said. "Investors were seen cashing in on Samsung Electronics shares after it announced record profit estimates this morning, and the index faced resistance around the 1,850 level." The Korea Composite Stock Price Index (KOSPI) was trading 1.36 percent lower at 1,838.44 as of 0235 GMT. Shares in Samsung Electronics Co Ltd retreated 1.33 percent as investors largely shrugged off a record fourth-quarter profit estimate from the world's largest smartphone and memory producer. Crude oil refiners, the best performers on the week so far, posted the sharpest falls after oil prices retreated on euro zone jitters and large US stockpiles, offsetting supply risks from simmering tensions between Iran and Western nations. SK Innovation, the holding company of South Korea's largest oil refiner, fell 2.27 percent while GS Holdings , parent to the country's second largest refiner, dipped 1.49 percent. Cyclical shares fell broadly, with POSCO, the world's third largest steel-maker by market value, dropping 2.55 percent, and Hyundai Engineering & Construction, South Korea's largest builder, sliding 2.36 percent. Institutional investors sold 84.3 billion won ($73.1 million) worth of shares, poised to snap a five-day buying streak.