Industry officials say the workforce contraction is heavily due to intensive restructuring at the five leading commercial banks. KB Kookmin Bank, Shinhan Bank, Woori Bank, KEB Hana Bank and Nonghyup together let go of 4,841 employees, the data showed. 

KB Kookmin, for instance, reduced its workforce by 2,592 people last year, the biggest number among all banks, with 2,795 leaving through voluntary retirement in January.

The number of branches decreased at an even greater scale. The banks had 6,790 branch offices at end-2017, down 312 from the previous year. It was the biggest decrease since record keeping began in 1999.

Citibank, which had 133 branches, reduced them to 44. Hana closed 87 branches, while KB Kookmin shuttered 71.

Customer preference for mobile and Internet banking will push these trends further, industry officials say, reducing the demand for manpower and physical spaces.

Data from the Bank of Korea said Internet banking transactions accounted for 83.9 percent in the fourth quarter last year, compared with 10.1 percent in over-the-counter transactions. (Yonhap)