SEOUL, May 7 (Xinhua) -- South Korea's foreign currency reserves fell last month as the strong U.S. dollar reduced the conversion value of non-dollar assets, central bank data showed Tuesday. Foreign reserves amounted to 404.03 billion U.S. dollars as of end-April, down 1.22 billion dollars from a month earlier, according to the Bank of Korea (BOK). The downturn came as the dollar ascent lowered the conversion value of non-dollar assets. The dollar index, which gauges the dollar value against six major peers, gained 0.7 percent in April from the previous month. The euro depreciated 0.4 percent versus the dollar, and the British pound declined 0.9 percent to the greenback. The Australian dollar and the Japanese yen slipped 0.3 percent and 0.9 percent each against the dollar last month. The foreign reserves were composed of 374.16 billion dollars of securities, 19.38 billion dollars of deposits, 4.79 billion dollars of gold bullion, 3.18 billion dollars of special drawing rights and 2.51 billion dollars of IMF positions. South Korea was the world's ninth-largest holder of foreign reserves as of end-March, down one notch from the prior month.