An electronic board showing the Korea Composite Stock Price Index at a dealing room of the Hana Bank headquarters in Seoul on Tuesday. (Yonhap)

South Korean stocks started higher Tuesday ahead of parliamentary elections and the release of key US inflation data later this week.

The benchmark Korea Composite Stock Price Index gained 18.76 points, or 0.69 percent, to 2,736.41 in the first 15 minutes of trading.

Overnight, major US indexes were almost flat as investors awaited the March consumer price index report, a key measure of inflation, to be released later this week.

Investors' eyes are also on the results of South Korea's parliamentary elections set to be held Wednesday.

In Seoul, market bellwether Samsung Electronics dipped 0.36 percent, while No. 2 chipmaker SK hynix climbed 0.88 percent.

Leading battery maker LG Energy Solution rose 1.74 percent, Samsung SDI increased 0.36 percent, and Posco Future M jumped 3.37 percent.

Auto and bio shares also gained ground.

Top carmaker Hyundai Motor added 1.08 percent, and its smaller affiliate Kia soared 3.32 percent.

Bio giant Samsung Biologics gained 0.74 percent, and Celltrion went up 0.58 percent.

The local currency was trading at 1,353.40 won against the dollar, down 0.20 won from the previous session's close. (Yonhap)