Seoul shares rise, led by STX units, but market under pressure

* STX affiliates rally on hopes of financial restructuring

* Auto part maker Mando up on report of new factory opening

* LG Display up on world's first full-HD phone panel; local media

By Joonhee Yu

SEOUL, May 29 (Reuters) - Seoul shares logged modest gains on Monday morning, led by STX units on news of group restructuring efforts, but the market remained under pressure as soaring Spanish borrowing costs added to euro zone debt crisis worries.

The Korea Composite Stock Price Index (KOSPI) was up 0.5 percent at 1,833.20 points as of 0220 GMT.

"Uncertainty in Europe is still shackling investors from taking any positions. Institutions picked up some bargains but the broader market is still wandering," said Lee Eun-taek, an analyst at Dongbu Securities.

Institution-managed funds picked up a net 73.1 billion won ($61.7 million) worth of shares while foreign investors, who are in the midst of an 18-day selling run, offloaded 10.2 billion won worth.

Shares in STX affiliates soared, after local media reports said cash-strapped STX Group was on the verge of signing an MOU with Korea Development Bank to oversee its financial restructuring efforts.

Listed units of the STX business group swept the leaderboard of top percentage gainers in the benchmark KOSPI 200 index as STX Offshore & Shipbuilding soared 7.3 percent while STX Pan Ocean rallied 6.5 percent and STX Corp rose 5.8 percent.

Shipyards lent support on bargain hunting, as Daewoo Shipbuilding & Marine Engineering rose 4.5 percent while Hyundai Mipo Dockyards advanced 3.5 percent.

Mando Corp, a South Korean automotive component-maker, saw its shares climb 3 percent after local media said it had completed the construction of a new production facility in Brazil.

Shares in screenmaker LG Display rose 2.5 percent after it developed the world's first, full high-definition LCD panel for smartphones, according to local media.

($1 = 1185.3500 Korean won) (Reporting by Joonhee Yu; Editing by Nick Macfie)