Wholesale prices were up 3.5 percent in September from a year earlier for the 18th straight month of increase, but the pace of gain continued to slow amid falling crude oil prices and the diminishing effects of the weaker yen, which has pushed up import prices.
The result almost matched forecasts by private-sector economists. The rate of rise was slower than an upwardly revised 4.4 percent in July and 3.9 percent in August.
The index of corporate goods prices stood at 106.3 against the 2010 base of 100, the Bank of Japan said in a preliminary report.
Excluding the impact of the 3-percentage-point consumption tax hike in April, the prices only rose 0.7 percent, the first time they have grown by less than 1 percent in 16 months.
On a month-on-month basis, wholesale prices fell 0.1 percent from August for the second straight monthly decline, in line with market forecasts, largely affected by recent falls in crude oil prices.
Prices for petroleum and coal products as a whole rose 6.7 percent from a year before. They gave upward momentum to the overall trend together with higher costs of raw material such as timber, iron and steel, and nonferrous metal products — amid demand from public works projects and smartphone manufacturing.
But the pace of gain has slowed in recent months on lower crude oil and gasoline prices, the BOJ said, adding that the effects of the weaker yen, which had pushed import prices significantly higher, have diminished nearly two years after the start of the currency's depreciation against the dollar and other major currencies.
Import prices rose 4.4 percent in September in yen terms, compared with a 17.9 percent rise in the same month a year before — the most recent peak. Meanwhile, export prices grew by 3.6 percent, up from 2.7 percent in August.