Seoul shares rise; automakers, Samsung Elec gain

* KOSPI trades firm, gains 0.6 pct

* Automakers up despite impending end of U.S. auto programme

* Samsung Elec gains after U.S. antitrust investigation ends

(Updates to mid-morning)

By Jungyoun Park

SEOUL, Aug 21 (Reuters) - Seoul shares rose on Friday, with Samsung Electronics (005930.KS) climbing after news a U.S. antitrust investigation involving the company had ended and automakers such as Hyundai Motor (005380.KS) continuing to rally.

The Korea Composite Stock Price Index .KS11 (KOSPI) was up 0.63 percent at 1,586.51 points as of 0116 GMT.

"Shares are trading in positive territory on the back of a firm ending on Wall Street, and as Chinese markets stabilised following their latest sharp falls," said Kim Young-june, a market analyst at SK Securities.

"But it is premature to say markets will make more meaningful and extensive gains...at this point we need stronger macroeconomic data that could assure investors global economies are headed for a firm recovery," Kim added.

Shares in Samsung Electronics advanced 1.62 percent after the world's No.1 memory chip maker and Japan's Toshiba Corp (6502.T) said on Thursday a U.S. Justice Department antitrust investigation involving the NAND flash memory business has ended. [ID:nSEO334481]

Daewoo Securities analyst Song Jong-ho said while the investigation news was a positive, "the main factor boosting Samsung Electronics shares today is its bullish third quarter earnings outlook," with hopes the firm's operating profit could hit the high 3 trillion won ($2.41 billion) range.

SK Chemicals (006120.KS) spiked 15 percent after news European trader Trafigure sealed a $48 million contract to lift 60,000 tonnes of biodiesel from the petrochemical firm next year. [ID:nSP463242]

Automakers rose despite news the U.S. government would suspend its popular "Cash for Clunkers" auto rebates on Monday, as the programme's $3 billion budget runs dry, a month after it was launched. [ID:nN209152]

"It's regrettable that the programme ended so soon, but the very fact that the fund dried so fast signals there is strong demand for new cars out there," said Koh Tae-bong, an analyst at IBK Securities.

"As economies pick up demand for South Korean cars will likewise rise," Koh added.

Shares in Hyundai Motor (005380.KS), South Korea's top automaker, were up 2.1 percent and Kia Motors (000270.KS) advanced 2.91 percent.

(Reporting by Jungyoun Park; Editing by Jonathan Hopfner)