Seoul shares rise on Fed comments; MSCI additions up

* KOSPI trades firm, rises 0.61 pct

* Tong Yang Securities, LS Industrial gain on MSCI addition

* LG Display advances for third session on Japan quake

(Updates to mid-morning)

By Jungyoun Park

SEOUL, Aug 13 (Reuters) - Seoul shares traded firm on Thursday after gains on Wall Street and positive comments by the U.S. Fed, with shares added to the MSCI Korea Index .MSCIKR including Tong Yang Securities (003470.KS) getting a lift.

The Korea Composite Stock Price Index (KOSPI) was up 0.61 percent at 1,574.91 points as of 0142 GMT.

"The Fed's comments helped ease concerns about a premature exit strategy or rate hike, helping sentiment in Seoul markets as well," said Choi Seong-lak, a market analyst at SK Securities.

The Federal Reserve said the economy was leveling out and left interest rate unchanged at the end of its two-day policy meeting. It also said it would extend the duration but not the size of a program to buy long-term government debt. [ID:nN12181240]

"If the index steadily ekes out gains, equity fund investors who have in recent weeks been redeeming their funds may halt their redemptions on expectations for an extended rally," Choi said, adding that the main index could touch as high as 1,800 points this year.

LS Industrial System Co (010120.KS) and Tong Yang Securities, which were added to the MSCI Korea Standard Index .MSCIKR, advanced 0.51 percent and 2.95 percent respectively.

"Normally this sort of announcement lifts the stocks for a couple of sessions or more," said Han Beom-ho, a market analyst at Goodmorning Shinhan Securities.

Shares in Unison (018000.KQ) spiked 14.7 percent after news the wind turbine parts manufacturer would soon sign a MOU with China's Fuxin city to supply it 1,000 2 megawatt wind power generating facilities over the next five years.

A company official told Reuters the two sides were still negotiating the price of the deal, which the market has estimated at 4 trillion won ($3.22 billion) according to a report by the Maeil Business Newspaper on Thursday.

"The news is definitely positive for Unison, and I'm very impressed with the reported scale and the size of the deal," said Choi Ji-hwan, an analyst at NH Investment & Securities.

Shares in liquid crystal display (LCD) panel maker LG Display (034220.KS) rose for a third session, gaining 4.17 percent, after an earthquake disrupted glass production in Japan, stoking fears shortages may intensify. [ID:nSEO37071]