Wholesale prices fell 1 percent in May on a year-on-year basis for the 33rd consecutive month of decline, according to a preliminary report released Wednesday by the Bank of Japan.

The margin of decline widened for the second month in a row, primarily reflecting a continuing fall in crude oil prices since April, BOJ officials said.

The corporate goods price index for May came to 94.9 against the 2000 base of 100, the central bank said.

The BOJ started using the CGPI in December, replacing the wholesale price index used previously.

The new gauge is aimed at measuring price trends more accurately and monitors changes in the prices of a wider range of goods.

The May CGPI reading shows a decrease of 0.3 percent from April, marking the second straight month of decline.

Wholesale prices of petroleum and coal products dropped 2.8 percent from the previous month, reflecting falls in gasoline prices in particular, the officials said.

Prices in the electrical machinery and equipment sector fell 0.5 percent from the previous month, primarily due to continued price competition in the computer and cell phone sectors, the officials said.

But wholesale prices of processed foodstuffs rose 0.2 percent from April, as prices of low-malt "happoshu" rose in the wake of a liquor tax hike, they said.

Export prices for May fell 3.1 percent in yen terms from a year before, with the export price index standing at 99.2.

When measured in terms of contractual currencies, export prices for the month fell 1 percent.

Import prices dropped 2.5 percent in yen terms, with the corresponding index registering 99.5. In terms of contractual currencies, import prices rose 1.8 percent from a year earlier.

The dollar averaged 117.32 yen in May, down from 126.44 yen in May 2002.