South Korea's current account surplus, the broadest measure of cross-border trade, is expected to surpass that of Japan this year for the first time, sources said Sunday. South Korea, Asia's fourth-largest economy, posted a current account surplus of US$42.22 billion in the January-August period of this year, according to the Bank of Korea. Japan, the world's No. 3 economy after the United States and China, recorded a current account surplus of $41.53 billion during the same period. In the first eight months of this year, South Korea topped Japan in terms of the current account surplus for the first time since 1980 when tracking of related data began, according to (Yonhap) news agency. For the entire year, South Korea is expected to register a current account surplus of $63 billion, larger than Japan's $60.1 billion, according to the sources. Analysts said South Korea's expected overtaking of Japan reflects economic conditions facing the two countries. South Korean exports of key products such as mobile phones and cars have been strong, while Japan's energy imports have been surging amid the weakness of its currency, they said. In September alone, South Korea logged a current account surplus of $6.57 billion, marking the 20th straight month of surplus.