* Samsung Elec falls 2.4 pct after Galaxy S4 launch
* Hyundai, Kia rebound as won weakens to 5-month lows
* Biopharma firm RNL BIO sinks 15 pct
By Somang Yang
SEOUL, March 15 (Reuters) - Seoul shares retreated on Friday as Samsung Electronics slipped after the launch of its new smartphone, but losses were plugged by the rebound in auto shares which were buoyed by a weaker won.
The Korea Composite Stock Price Index (KOSPI) ticked 0.7 percent lower to 1,988.62 points as of 0218 GMT.
Samsung Electronics, South Korea’s most valuable stock which accounts for nearly a fifth of the KOSPI’s market capitalisation, fell by 2.4 percent.
Market watchers said that the much-awaited Galaxy S4 may have disappointed investors who had overblown expectations following months of speculation regarding new features. The phone sports a bigger display and unconventional features such as gesture controls.
However, auto shares roared back as the won hit a 5-month low against the dollar, easing fears that Japanese cars had an unfair price advantage abroad.
Shares in Hyundai Motor rose 2.8 percent while sibling Kia Motors was up 2.3 percent.
“The index will struggle to find upward momentum as the recovery in the United States isn’t shared by other markets,” said Park Hyung-joong, an economist at Meritz Securities.
Among daily movers, stem-cell product maker RNL Bio plunged by the daily permissible limit after the firm said on Thursday that its capital impairment percentage exceeded 50.
Overall, declining shares just outnumbered winners 393 to 380.
The KOSPI 200 benchmark of core stocks was down 0.8 percent, while the junior KOSDAQ was flat. (Reporting by Somang Yang; Editing by Jacqueline Wong)