The Korea Composite Stock Price Index (KOSPI) ticked 0.02 percent lower at 1,980.03 points as of 0230 GMT.

"Several factors weighed on the main board, including profit-taking on the volatile won and Apple's earnings. But China's PMI was solid, supporting the index," said Kim Young-joon, an analyst at SK Securities.

The HSBC flash purchasing managers' index (PMI) rose to 51.9 in January, the highest since January 2011, indicating a steady recovery in the world's second-largest economy.

Tech shares were down, with heavyweight Samsung Electronics sliding 0.8 percent while LG Display, an Apple component supplier, fell 2.1 percent.

Hyundai Motor shares fell 1.6 percent near the mid-session ahead of its fourth-quarter earnings due later in the day.

A Reuters poll of 15 analysts forecast its October-December net profit rose 7.5 percent to 2.15 trillion won ($2 billion), the automaker's lowest profit growth since it switched accounting rules in 2011.

Hyundai's record car sales are seen dented by the impact of a stronger local currency and the cost of compensating drivers in North America for overstated fuel-economy claims.

Foreign investors sold a net 90.2 billion Korean won ($84.60 million) worth of KOSPI shares near mid-session, weighing on the index.

Declining shares outnumbered winners 392 to 349.

The KOSPI 200 benchmark of core stocks was down 0.1 percent, while the junior KOSDAQ traded flat.