The National Personnel Authority, the government body that supervises public servants, has decided to introduce a performance-based wage system for civil servants, abolishing automatic annual wage hikes based on seniority, government officials said Friday.

The agency wants to introduce the performance-based system in fiscal 2006.

But it may be tough to get the measure approved, with the union and government ministries expected to oppose the plan.

These bodies are expected to likely cite difficulties in devising clear standards for assessing appropriate wage levels for the nonprofit work that civil servants perform.

The agency is already discussing the matter with the union and intends to include its basic policy in its annual salary recommendation for government employees, which will be issued in August.

The agency's move is in keeping with the government's plan to submit draft bills concerning the introduction of a performance-based system to the next extraordinary Diet session in the fall.

Many Japanese firms have introduced performance-based salaries, shifting away from the traditional seniority-based wages. The agency has been considering adopting this kind of system for civil servants amid strong criticism of the government's seniority-based system, the officials said.

The agency initially plans to introduce a performance-based system for basic salaries before eventually applying the system to bonuses, the officials said.

Chief Cabinet Secretary Hiroyuki Hosoda told a regular news conference Friday that the government welcomed the agency's decision.

"The system has already been introduced by many private companies," he said "It is desirable that public servants be assessed for their performance and have differences in their wage hikes."

The agency makes wage recommendations every year for central government staff, taking private-sector wages into account because the labor rights of civil servants are restricted under law.