Wholesale prices grew for the second straight year in 2014 on higher energy and raw material costs, but the pace slowed significantly in December amid the sharp fall in crude oil prices, the Bank of Japan said Thursday in a preliminary report.

The central bank's index of corporate goods prices rose 1 percent to 102.9 for last year against the 2010 base of 100, after excluding the impact of the 3-point consumption tax hike in April to 8 percent from 5 percent.

Electricity, gas and water prices grew 7.7 percent from 2013. Gasoline and coal products prices gained 3.7 percent while iron and steel logged a 2.9 percent rise.

Such price increases were largely caused by the BOJ's weakening of the yen, which boosted the cost of imported energy and raw materials as the central bank looks to stoke inflation.

Bucking the trend, prices for electronic components and devices fell 3.6 percent on global price competition amid the spread of smartphones and tablet computers.

Agriculture, forestry and fishery products prices shed 2.1 percent, while information and communications equipment fell 2.3 percent.

In December alone, the wholesale price index rose 1.9 percent from a year earlier to 104.8, the BOJ said in the preliminary report.

The index climbed for the 21st straight month, but the rise was the lowest since last March, and came after a downwardly revised 2.6 percent increase in November.

Excluding the impact of the sales tax, the index dropped 0.9 percent in the second consecutive monthly fall, expanding the pace of decline from November's 0.2 percent.

Gasoline and coal product prices slid 8.8 percent from a year before and 5.7 percent from November, as oil prices slumped more than 60 percent in the last seven months.

Prices rose 0.5 percent for imports and 5.9 percent for exports year-on-year in yen terms, affected by the drop in the currency's value