Key corporate labor unions filed their wage demands for the year with management Friday, kicking off the year's "shunto" spring wage negotiations.

Their demands focus on maintaining regular pay hikes amid the country's economic conditions and tough employment situation. Under a regular wage hike system, workers have so far been granted an automatic pay increase as their seniority advances.

The Japanese Trade Union Confederation (Rengo), the nation's largest umbrella labor body, is forgoing its demands for a pay-scale increase and instead is calling for ensuring regular pay hikes this year.

Unions that filed their wage demands Friday were members of the Japan Federation of Basic Industry Workers' Unions, a key Rengo component, which is formed by unions at firms in such key industry sectors as steel, shipbuilding and nonferrous metals.

Automotive unions, which form the Confederation of Japan Automobile Workers Unions, are scheduled to file their demands Wednesday and members of the Japanese Electrical, Electronic & Information Union by Thursday.

Wage talks will continue on and off for more than a month before management makes their offers in response to the demands on March 17.

On Friday at the Tokyo head office of Japan's top steelmaker, Nippon Steel Corp., its union and management representatives held talks.

Union leader Kazuhiko Miyazaki filed his union's demands with Nippon Steel Executive Vice President Kosei Shindo, saying the union attaches importance to ensuring workers' employment and maintaining their livelihood.

Member unions of the Japan Federation of Basic Industry Workers' Unions hold wage talks once in two years.

In this year's talks, unions of Nippon Steel and Kobe Steel Ltd. are demanding that management maintain regular pay hikes.