Wholesale prices rose in April from a year earlier, marking a second straight year-on-year increase, the Bank of Japan said Monday in a preliminary report.

The figures also represented the biggest percentage gain in four years, the BOJ said.

The prices, measured by the central bank's corporate goods price index, registered 95.6 against the 2000 base of 100, up 0.5 percent from the previous year's level. The gain was the sharpest since April in 2000, when the CGPI rose 0.6 percent.

In March, the CGPI rose 0.2 percent from a year earlier.

Rises in steel and nonferrous metal products pushed the index higher, indicating deflation may be coming to an end, the report says.