* KOSPI down 0.4 pct at 1,936.76 points
* Automakers up as Hyundai Motor union agrees to resume work
* Chemicals lose ground as OCI says Suntech orders cancelled
SEOUL, April 29 South Korean shares fell on Monday as weaker-than-expected U.S. gross domestic product data weighed on investor sentiment.
The Korea Composite Stock Price Index (KOSPI) slipped 0.4 percent to 1,936.76 points as of 0211 GMT.
"I have a conservative view of the global economy in the current quarter, and with South Korea's stimulus struggling to gain traction here, South Korean companies will suffer at home and abroad," said Park Hyeong-joong, an analyst at Meritz Securities.
Automakers bucked the trend, however, after Hyundai Motor's labour union agreed to restart weekend production from this week following output stoppages in March and April over wages that hit sales and earnings.
Hyundai gained 1.8 percent, while Kia Motors rose 3 percent.
"There are expectations that automakers' profitability would improve in the second quarter, with increased domestic production and utilization rates," said Jang Moon-soo, an analyst at Eugene Investment & Securities.
OCI slumped after the chemicals firm said on Friday that three polysilicon orders worth 1.46 trillion Korean won ($1.31 billion) from units of China's solar panel maker Suntech Power Holdings Co Ltd were cancelled because of the latter's financial troubles.
OCI was down 4.5 percent by late morning, after falling as much as 9.5 percent earlier in the day, leading losses in the chemicals sector.
Telecom firms, seen as defensive stocks, gained ground, with LG Uplus up 4.8 percent and SK Telecom gaining 3.1 percent. (Reporting by Hyunjoo Jin; Editing by Kim Coghill)