Korean manufacturers' business confidence for May moved up for the fourth straight month as overall economic conditions showed signs of steady improvement, the central bank said Monday.

The business survey index (BSI) of manufacturers' expectations rose to 90 for May from 85 tallied in April, according to the Bank of Korea (BOK).

The reading follows recent improvements in the BSI that started from February onwards after dropping to 79 in the first month of this year.

The index measures manufacturers' outlook on business conditions for the coming month. A reading below 100 means pessimists outnumber optimists. The nationwide survey of 2,505 companies was conducted from April 16-23.

"The rise in the Korean manufacturers' business sentiment reflects recent indications that the economy is expanding at a steady pace despite lingering uncertainties," the BOK said.

The central bank said last week that Asia's fourth largest economy pulled off a solid 0.9 percent growth in the first quarter compared to the previous three-month period. It said that the growth was a better-than-expected showing in light of uncertain global economic conditions.

The latest report showed that business confidence among large companies and exporters reached 98 and 94, respectively, more upbeat than small and medium firms with 86 and non-exporters with 87.

Korea, which grew 3.6 percent in 2011, is expected to expand 3.5 percent this year. (Yonhap)