The rise in the corporate goods price index (CGPI), which measures the price companies charge each other for their goods and services, exceeded a median market forecast for a 9.5% gain.

It followed a revised 9.7% increase in November, Bank of Japan (BOJ) data showed.

The yen-based import price index rose 22.8% in December from a year earlier, slowing from a revised 28.0% gain in November, in a sign the currency's recent sharp ascent helped reduce the cost of importing fuel and raw material.

(Reporting by Leika Kihara)

By Leika Kihara