Japan's domestic wholesale prices fell 1.2 percent in May from a year earlier for the 20th consecutive month of decline.

The pace of the slide, however, was unchanged from the previous month, the Bank of Japan said Monday.

The domestic wholesale price index stood at 94.4 against the 1995 base of 100. The index was unchanged from April, remaining flat for the third straight month.

Prices fell 4.1 percent from a year earlier for electric machinery, 3.2 percent for chemicals, 2.9 percent for wood and lumber products, 2.2 percent for pulp and paper, and 1.5 percent for transportation equipment, the central bank said.

But prices rose 5.4 percent for petroleum and coal products due to tensions in the Middle East, 0.3 percent for nonferrous metals and 0.3 percent for edible farm, livestock and fishery products. Consumers appeared to prefer higher-priced domestic products amid mislabeling scandals.

Export prices, measured in yen, rose 0.6 percent from a year earlier but fell 2.5 percent from April on a stronger yen. Export prices gained for stainless steel plates and other metal products as well as chemicals, but dropped for microchips and other electric equipment and machinery.

Import prices, also measured in yen, fell 0.6 percent from a year earlier and 1.9 percent from April on a stronger yen. Import prices slipped for microchip and other electric machinery and equipment but rose for crude oil and wood products.