By Leika Kihara

TOKYO (Reuters) - Many regional areas of Japan saw small and mid-sized firms aggressively raise wages, reflecting intensifying labour shortages, the Bank of Japan (BOJ) said on Monday, underscoring its growing conviction that wage hikes were broadening.

In a quarterly report, the central bank also said some firms were considering raising prices of their goods and services to guard against prospects of rising labour costs.

"Many regions reported cases where wage increases by small and mid-sized firms were broadening at a degree unseen in recent years," the BOJ said in the report analysing the economic situation of regional areas.

The BOJ raised its economic assessment for three of Japan's nine regions, and maintained that for the remaining six regions.

"All of the regions saw economic growth pick up or recover moderately," the report said.

Wage growth holds the key to how soon the BOJ phases out its massive stimulus programme.