Producer prices in Japan rose in October, marking the 20th consecutive month of increase. Rising costs for raw material are pushing up the prices of a wide range of products sold to companies.

The Bank of Japan says the cost of goods traded among companies increased 9.1 percent in October from a year earlier.

The rise is slower than the double digit increase recorded in September, but last month's figure is still relatively high.

The increase was mainly due to higher prices for steel, electricity, as well as food and beverages. Of the 515 items covered by the survey, over 80 percent were more expensive. That suggests companies have been hit with higher procurement costs and are passing them on in their products and services.

The Import Price Index surged 42.6 percent year-on-year in yen terms, as the Japanese currency continued to slide against the US dollar.

The BOJ says there are still great uncertainties, due to fluctuations in raw material prices and the weaker yen.

The officials say they will closely monitor trends in import prices and firms' moves to pass on higher costs by raising the prices of what they sell to other businesses.