(Updates to midday)
* Almost steady after hitting 3-mth high as U.S. data awaited
* Auto shares rise after Hyundai labour deal
* SK Hynix falls again after China plant fire
SEOUL, Sept 6 South Korean shares briefly hit a fresh three-month high on Friday before paring gains as investors grew cautious ahead of key U.S. jobs data which could impact the Federal Reserve's plans to begin scaling back its stimulus programme.
The Korea Composite Stock Price Index (KOSPI) was up 0.2 percent at 1,955.09 points as of 0240 GMT after hitting 1,957.21, the highest intraday level since June 5.
U.S. non-farm payrolls data due later on Friday, if firm, is expected to cement the case for the U.S. Federal Reserve to begin scaling back stimulus later this month.
Concerns about the global impact of Fed tapering have roiled emerging markets since late May but South Korean shares have recently shown signs of regaining traction.
"The market isn't seeing much action as investors await the U.S. data," said Dongbu Securities analyst Lee Eun-taek. However, "foreign inflows and Hyundai Motors' rally are underpinning the benchmark."
Foreign investors were net buyers of 123.6 billion won ($112.53 million) worth of local stocks in the morning, extending their buying streak to an 11th consecutive session.
Automaker Hyundai Motor Co rose 2.1 percent to its highest in nearly a year after it settled on a tentative deal with the South Korean labour union late on Thursday.
Hyundai Motor's affiliates Kia Motors Corp and Hyundai Mobis Co Ltd also jumped, advancing 2.7 percent and 1.8 percent, respectively.
Hyundai Mipo Dockyard Co Ltd gained 1.7 percent as stronger global economic outlook enhanced hopes of better earnings in the coming quarters. The shipbuilder is on pace to post its second-highest weekly gain for the year to date.
Steel makers also rose on prospects of increased earnings, with Hyundai Steel Co rising 3.6 percent and POSCO gaining 1.2 percent.
SK Hynix Inc fell 1.8 percent, declining for the second straight session after operations at its main Chinese plant had been suspended due to a fire. Its shares dipped 1.7 percent on Thursday.
Decliners outnumbered gainers 436 to 325.
The KOSPI 200 benchmark of core stocks gained 0.1 percent, while the junior KOSDAQ edged 0.1 percent lower. ($1 = 1098.3750 Korean won) (Reporting by Jungmin Jang; Additional reporting by Hyunjoo Jin; Editing by Choonsik Yoo & Kim Coghill)