Seoul shares fall amid econ worries; techs lead

* KOSPI falls for third session

* Kumho Industrial tumbles after capital writedown plan

* Shinhan Financial shares sink after investigation report

(Updates to close)

By Jungyoun Park

SEOUL, Aug 25 (Reuters) - Seoul shares extended falls to a third session on Wednesday, as an unexpectedly large drop in U.S. home sales fueled concerns about global economies, sending key technology exporters such as LG Electronics (066570.KS) lower.

The Korea Composite Stock Price Index .KS11 (KOSPI) closed down 1.46 percent to 1,734.79 points.

"Concerns about economies are deepening following weaker than expected U.S. home sales data...I think the market will continue to be weighed by broader worries about the economic outlook for some time," said Lim Dong-min, a market analyst at KB Investment & Securities.

Sales of previously owned U.S. homes took a record plunge in July to their slowest pace in 15 years, underlining the housing market's struggle to find its footing without government aid.[ID:nN24249810]

Foreign investors were sellers of a net 199.4 billion won ($167.4 million) worth of stocks, snapping a five-session buying streak.

Blue chip exporters led falls. Samsung Electronics (005930.KS), the world's No.1 memory chip maker and the largest stock on the KOSPI, lost 1.4 percent, and LG Electronics, the world's No.3 handset maker, shed 3 percent.

"LG Electronics shares came under particularly heavy pressure, as its third quarter earnings are seen improving little from disappointing second quarter figures," said Park Seong-min, an analyst at Kyobo Securities.

Steelmakers also lost ground, with POSCO (005490.KS), the world's No.3 steelmaker, losing 1.2 percent and Hyundai Steel (004020.KS) declining 2.9 percent.

State-run power company KEPCO (015760.KS) outperformed, gaining 1.3 percent, on easing uncertainties after the government laid out on Tuesday a plan to reform the power industry.

The Ministry of Knowledge Economy said that it planned to link electricity prices to energy generation costs, which would help reduce losses for state-run power companies.

"Under the current system, KEPCO is selling electricity below cost," said Jeong Min-kyu, an analyst at IBK Investment and Securities.

Shares in Shinhan Financial Group (055550.KS) lost 1.9 percent after a local media report that regulators were examining whether its chairman Ra Eung-chan had violated a financial law, allegedly using a Shinhan Bank account.

The Financial Supervisory Service said later on Wednesday it had requested documents from Shinhan Bank but had made no findings so far.

Kumho Industrial (002990.KS) stocks plunged by the daily limit of 15 percent after the company said late on Tuesday it would undergo a massive capital writedown.

The firm is a construction unit of Kumho Asiana Group under a creditor led-restructuring programme.