The Bank of Korea said in a statement its manufacturing business survey index for October climbed to a seasonally adjusted 82 from 78 in September and 74 in August. It was at its highest since reaching 83 in May last year.
Its combined gain of 8 points during the September-October period also marked the biggest rise in any two-month period since posting a 12-point jump in September-October of 2009, the central bank data shows.
The latest reading remained below 100, indicating the number of companies expecting a deterioration in business conditions for the coming month outpaced those predicting improvement, but it tends to stay low even during better times.
Caution among South Korean manufacturers, which rely heavily on exports for their overall business performance, reflected an uncertain outlook for global demand, which is still far from showing a firm pick-up.
South Korean exports grew just 1.7 percent in January-August compared with the same period last year and are expected to post 2 percent growth in September, a Reuters poll shows, well below an average of 14 percent for the past 10 years.
The central bank said it surveyed 1,503 manufacturers representing 23 major industries between Sept. 11 and 23.