Seoul shares flat; exporters up, refiners down

*Exporters rise on weakness in the won

*Steelmakers lower on China competition

*Energy shares down outlook worries

(Updates to midmorning)

By Park Jung-youn

SEOUL, Aug 12 (Reuters) - Seoul shares traded slightly lower
on Tuesday after the previous session's gains, with easier oil
prices continuing to support exporters such as Samsung Elec
(005930.KS), but oil refiners fell on outlook worries.

The Korea Composite Stock Price Index was down 0.03
percent at 1,580.64 points as of 0102 GMT.

"Major market factors have turned positive for the market
lately, but investors remain cautious today ahead of options
expiry later this week," said So Jang-ho, an analyst at Samsung
Securities.

Exporters in tech and manufacturing sectors were up, with
Samsung Electronics (005930.KS), the world's No.1 memory chip
maker, up 1.71 percent to 595,000 won, and LG Electronics
(066570.KS), the world's No.4 handset maker up 3.39 percent to
122,000 won.

Hyundai Motor (005380.KS), South Korea's top car maker,
traded 2.88 percent higher at 75,000 won, and Kia Motors
(000270.KS), its smaller affiliate was up 3.42 percent to 13,600
won.

However, energy shares retreated with the recent fall in
crude prices on prospects of a demand slowdown making the outlook
for refiners more uncertain, analysts said, predicting oil
product prices could weaken in the second half.

Falls were led by GS Holdings (078930.KS), a holding firm of
GS Caltex, which fell 2.31 percent to 31,650, continuing its
downward run for a second day on worries about the financing
burden of its bid for Daewoo Shipbuilding & Marine Engineering
(042660.KS).

SK Energy (096770.KS) fell 1.77 percent to 94,300 won, and
S-Oil (010950.KS) fell 0.63 percent to 63,300 won.

Steelmakers continued to underperform on deepening worries
that slowing global economies would dent demand for steel
products, coupled with costlier imports of raw materials because
of the weaker won currency.

Shares in POSCO (005490.KS) were down 0.94 percent to 472,500
won and Hyundai Steel (004020.KS) fell 0.7 percent to 56,700 won.

"China's steel export volume in July was quite high, jumping
21 percent from a year ago ... and this raises more uncertainties
for [South Korean] steelmakers," said Park Hyun-wook, an analyst
at Hyundai Securities.

Some shipbuilders rose after their latest falls and after the
latest rise in the Clarkson Research Studies' Newbuilding Price.
Index.

"Demand for increasingly scarce 2011 delivery berths, along
with rising cost pressures, are driving contract prices higher,"
said BNP Paribas, a French brokerage, in its note.

"(A cyclical) rise in vessel prices and shift in product mix
toward larger and value-add segments in line with Korea's
first-tier status continue to drive the global dominance of
Korean shipbuilders."

Shares in Hyundai Heavy Industries (009540.KS) rose 1.12
percent to 271,500 won and Daewoo Shipbuilding & Marine
Engineering went 2.15 percent to 38,050 won.