Belgium's senate on Thursday approved a plan, already passed by the lower house of parliament, to force state and public companies to give women 30 percent of seats on management boards.

The legislation provides for the quota system to come into force from next year in state-owned companies such as telecoms operator Belgacom, the postal service and the lottery.

Under the new rules, each time a board member ends his mandate he is to be replaced by a woman until the 30 percent quota is fulfilled.

A majority of 36 senators voted for the measure, while 22 voted against and eight abstained, according to a count provided by the Belgian press agency.

Companies quoted on the stock exchange will have five years to reach the 30 percent quota, except small- and medium-sized firms which will be given eight years to attain it.

The law, which the lower house approved on June 16, is to be re-evaluated in 12 years.

In establishing gender hiring quotas, Belgium is following the examples set first by Norway and later by France.

The European Commission wants more diversity on management boards and has looked at the feasibility of imposing hard quotas.