SEOUL, April 5 (Reuters) – South Korea shares edged up 0.09 percent to a fresh 21-month closing high on Monday, as key exporters such as Samsung Electronics (005930.KS) extended gains on steady foreign buying, offsetting weakness in shipyard stocks.

The Korea Composite Stock Price Index (KOSPI) finished up 1.50 points at 1,724.99 points.

Foreign investors were buyers of a net 186 billion won ($165.2 million) worth of shares, picking up stocks for a 17th consecutive session, the longest buying streak since August, 2008. Domestic institutions were sellers of a net 292 billion won.

Shares in Samsung Electronics finished up 1.52 percent to 870,000 won, hitting a new historical closing high, while LG Display (034220.KS) advanced 2.21 percent.

“Foreign appetite towards Samsung Electronics shares will hold up steadily as the company is expected to post record high earnings for this quarter, and such earnings momentum is set to continue into second quarter. We see shares rising to 900,000 won without much difficulty,” said Hong Hyeon-ki, equity management head at Dongbu Securities.

The company is expected to release its earnings guidance tomorrow.

Samsung Electronics, the world’s biggest electronics firm by revenue, saw shares receive a further boost by news that Apple Inc’s (AAPL.O)’s iPad carries parts that it manufactures.

Shares of Hyundai Motor (005380.KS), South Korea’s top automaker, continued their rise following strong March sales and were up 1.95 percent to a new record closing high of 130,500 won.

NHN Corp (035420.KS) ended up 2.16 percent after South Korea’s top Internet portal and Web search service said on Monday it was considering buying Japanese Internet portal Livedoor Co. to strengthen its operations in Japan.[ID:nTOE63400J]

“Livedoor is a prominent blog service provider [in Japan] and its acquisition is expected to strengthen NHN’s positioning in Japan,” said Wayne Lee, an analyst at Woori Investment & Securities.

Meanwhile shipbuilders fell across the board, with Daewoo Shipbuilding & Marine Engineering (042660.KS) declining 4.07 percent and STX Offshore & Shipbuilding (067250.KS) down 5.95 percent.

“Shares in shipyards are under pressure as there are little signs of improvements in fundamentals, while raw material prices are seen going up,” said Joey Lee, an analyst at Shinhan Investment Corporation, adding that some order cancellations or delays were also expected this year.

Banks also retreated, led by Woori Finance Holdings (053000.KS), which lost 4.68 percent.

Construction and shipbuilding sectors’ continued sectoral difficulties pointed to banks’ exposure to the sectors and dampened sentiment towards the issues, analysts said. Decliners outnumbered advancers 540 to 274, with 53 issues ending flat.

Trading volume stood at 415.4 million shares worth 5.4 trillion won, compared with 343 million shares worth 6 trillion won in the previous session.

The KOSPI 200 June futures index KSc1 ended up 1.50 points at 228.55, and the KOSPI 200 spot index .KS200 rose 0.79 points at 227.48.

The junior Kosdaq market .KQ11 ended 1.91 percent lower to close at 505.13.

Move on day +0.09 percent

12-month high 1,731.00 5 APRIL 2010

12-month low 1,260.73 8 APRIL 2009

Change on yr +2.5 percent

All-time high 2,085.45 1 NOV 2007

All-time low 93.10 6 JAN 1981 (Reporting by Jungyoun Park; Editing by Vikram Subhedar)