* Blue-chips mostly up; Samsung Elec, Hyundai Motor gains
* POSCO edges down on Fitch's ratings downgrade
SEOUL Nov 27 Seoul shares were up on Tuesday as news of debt target agreements for Greece and hopes for resolution of a potential U.S. fiscal crunch dispelled some of the uncertainty seen in the previous session.
The Korea Composite Stock Price Index (KOSPI) ticked 0.95 percent higher at 1,926.66 points as of 0204 GMT.
"The news of the Greek debt deal, plus U.S. fiscal cliff talks resuming this week, has spurred investor appetite," said Kim Young-joon, an analyst at SK Securities.
He said ongoing program buying from state and regional governments is expected to continue until the KOSPI reaches 1,950 points.
Euro zone finance ministers and the International Monetary Fund clinched agreement on reducing Greece's debt on Monday in a breakthrough to release urgently-needed loans to keep the near-bankrupt economy afloat.
Blue-chips were mostly up, with market heavyweight Samsung Electronics Co climbing 1.1 percent to edge closer to its lifetime closing high reached on Friday.
Hyundai Motor Co rose 3 percent around mid-session, extending Monday's gain after falling 14 percent between end-September and Friday. Affiliates like Kia Motors Corp and Hyundai Mobis Co Ltd also gained ground.
However, steelmaker POSCO bucked the trend by sliding 0.5 percent after credit rating agency Fitch Ratings downgraded POSCO to 'BBB+' from 'A-' after Monday's market close.
Among large movers, shares in Taihan Electric Wire Co Ltd rose 3.7 percent during Tuesday's trading, gaining for the fourth straight session.
Taihan Electric Wire's largest shareholder, Taihan Systems, is set to sell 50 percent of Taihan Electric Wire's warrants to Taihan Fiberoptics Co Ltd, an affiliate majority owned by a local private equity fund, a spokeswoman for Taihan Electric Wire said Tuesday.
In return, Taihan Electric Wire will receive about 60 billion won ($55.28 million) next month, local newspaper Korea Economic Daily reported Tuesday.
Local institutional investors net purchased 193.7 billion Korean won ($178.45 million) worth of KOSPI shares near mid-session, buttressing the index. Advancing shares outnumbered decliners 407 to 364.
The KOSPI 200 benchmark of core stocks was up 1.1 percent, while the junior KOSDAQ edged 0.1 percent higher. ($1 = 1085.4500 Korean won) (Reporting by Joyce Lee; Editing by Eric Meijer)