Standard Chartered bank said net profit fell more than 16% in 2013 and warned of a difficult first half for 2014 following significant challenges for its South Korean operations.

The London-based lender, which makes 90% of its profits in Asia, the Middle East and Africa, said net profit was $3.99bn last year, down 16.65% from $4.79bn in 2012.

Standard Chartered’s South Korean retail bank suffered a $1.0bn write-down in its value, and produced lower revenue with higher bad loans during the year, culminating in a $162mn operating loss.

Overall operating income fell one% to $18.67bn in 2013, compared to the previous year, while annual profit before tax was down 11% to $6.06bn.

The results follow a decade in which the bank posted consecutive full-year profits. Consumer banking income for the group grew by two% to $7.18bn, while wholesale banking income fell two% to $11.49bn. The bank’s chief executive Peter Sands warned of a weak performance for the first half of 2014 following weak growth in the past quarter. Income from consumer banking in China grew eight% to $321mn, but fell 12% to $1.05bn in South Korea.