The current account surplus swelled 50.3 percent in April from a year earlier to 1.99 trillion yen for the fourth straight monthly increase, spurred by firm exports and income account gains, the Finance Ministry said Wednesday.

The current account surplus hit its highest level for the month of April and the third-highest for any month since comparable data became available in January 1985, the ministry said in a preliminary report.

The income surplus, net income from Japanese investments overseas, gained 41.5 percent to 1.56 trillion yen. It grew as interest income and stock dividends from overseas investment increased, a ministry official said.