* Samsung Elec down 2.6 pct, hurt by yen and Forbes article
* Some defensives favoured; Hotel Shilla up 4.8 pct
By Joyce Lee
SEOUL, March 7 (Reuters) - Seoul shares fell on Thursday, with blue-chip exporters leading declines as renewed weakness in the yen and concerns about the risks posed by North Korea prompted investors to lock in profits.
A Forbes article that cited an analyst who recommended selling Apple and Samsung Electronics due to thinning profit margins, also helped push shares in the index heavyweight lower.
The United Nations Security Council is set to vote on sanctions that would tighten financial restrictions on North Korea in response to its third nuclear test.
"North Korean risk cannot be ignored, as events point to escalating tension as North and South Korea trade warnings and threats," said Koh Seung-hee, an analyst at SK Securities.
The Korea Composite Stock Price Index (KOSPI) dropped 0.8 percent to close at 2,004.40 points, off a two-month high marked on Wednesday.
Although a slowing pace in declines in the yen had helped the KOSPI gain 3.3 percent in February, the dollar rose to hit one-week high against the yen on Thursday. A softer yen benefits Japanese exporters directly competing with South Korean firms.
Samsung, which account's for 17 percent of the KOSPI's market capitalization, closed down 2.6 percent.
Cyclicals were down across the board, with Hyundai Motor falling 0.7 percent while steelmaker POSCO slipped 0.4 percent.
Investors flocked to some defensives, with Hotel Shilla gaining 4.8 percent while SK Telecom rose 1.9 percent.
Local institutional and foreign investors sold a net 151 billion won ($139.47 million) worth of KOSPI shares.
Decliners outnumbered gainers 511 to 291.
The KOSPI 200 benchmark of core stocks closed down 0.9 percent, while the junior KOSDAQ fell 0.6 percent.
Move on day -0.8 percent
12-month high 2,057.28 14 March 2012
12-month low 1,769.31 25 July 2012
Change on yr -1.3 percent
All-time high 2,231.47 27 April 2011
All-time low 93.10 6 January 1981 ($1 = 1082.6500 Korean won) (Additional reporting by Seongwon Chang; Editing by Edwina Gibbs)