Seoul shares fall on RBA rate hike; Samsung down

* Foreign investors turn net sellers after Australia rate hike

* Samsung Q3 guidance beats fcast; Q4 may be worse -analysts

* Refiners rise on crude prices' modest rebound

(Update to close)

By Jungyoun Park

SEOUL, Oct 6 (Reuters) - Seoul shares fell on Tuesday pressured by news of a rate hike by the Reserve Bank of Australia that fuelled foreign selling appetite, while Samsung Electronics slipped despite strong third-quarter earnings guidance.

The Korea Composite Stock Price Index .KS11 ended down 0.53 percent at 1,598.44 points, falling for a fourth consecutive session.

"The rake hike by Australia, which came far earlier than expected, weighed on sentiment as it pointed to the possibility South Korea may be next to raise rates," said Lee Sun-yeop, a market analyst at Shinhan Investment Corporation.

Foreign investors were sellers of a net 28 billion won ($24.03 million) worth of stocks, offloading Seoul shares for an eighth consecutive session. But they remain net buyers of 4.3 trillion won so far this year, following a non-stop monthly buying streak from March to September.

"Foreign investors are not selling out massively, and I do not think their selling will be an established trend. But without foreign buying, markets are faced with lack of buying activity as institutions are selling as well amid equity fund redemptions," Lee added.

Analysts expect the benchmark index to find support at the 60-day moving average of 1,590, after climbing to a 15-month closing high late last month.

Samsung Electronics (005930.KS), the world's top maker of memory chips and flat screen TVs, fell despite issuing a strong consolidated profit forecast for the third quarter thanks to gains in market share. [ID:nT89846]

Shares in Samsung Electronics, the largest stock on the main board, shed 0.27 percent, after rising as much as 1.9 percent.

"There are concerns that its third quarter earnings may be its short-term peak. Looking ahead at the fourth quarter and the first quarter next year, both a stronger won KRW= and a likely increase in marketing costs are set to weigh on earnings," said Lee Sun-tae, an analyst at Meritz Securities.

Samsung Electronics stocks have soared 66 percent on the year to date, outperforming the wider market's 43 percent rise.

Shares in POSCO (005490.KS) and LG Display (034220.KS), which will kick off the third-quarter earnings season next week, declined 1.66 percent and 0.62 percent respectively.

LG Electronics Inc (066570.KS), the world's No.3 handset maker, rose 3.17 percent, recouping part of the previous day's heavy falls.

Banking issues declined across the board, with KB Financial Group (105560.KS) shedding 1.54 percent and Woori Finance Holdings (053000.KS) down 2.56 percent.

But energy issues eked out modest gains helped by rebound in crude prices CLc1.

S-Oil (010950.KS), South Korea's No.3 crude refiner, rose 1.59 percent and GS Holdings (078930.KS), the holding company of refiner GS Caltex, went up 1.72 percent.

($1=1165.2 Won)