Korean parts makers last year shipped products worth almost W10 trillion to foreign automakers (US$1=W1,071).
Until the early 2000s, it was rare for parts makers here to do business with firms other than Hyundai and Kia or other domestic companies.
The Korea Auto Industries Cooperative Association said Monday that some 300 suppliers exported an estimated W9.66 trillion worth of components to Chrysler, Ford, GM, Nissan and Volkswagen in 2013.
The figure has been on the increase since 2011 when it stood at W5.4 trillion.
The statistics include sales of products manufactured in the parts makers' plants overseas.