BERLIN (AFP) - Germany's biggest companies will be required to have women fill a third of their supervisory boards from next year under a law adopted in parliament on Friday.
Two days before International Women's Day - and after years of wrangling over the issue - lawmakers in the Bundestag lower house of parliament widely approved the quota.
Family Minister Manuela Schwesig hailed the move, which kicks in from 2016, as a "historic step for women's equality".
Justice Minister Heiko Maas said the quota was the "biggest contribution to equality" since women won the right to vote in Germany in 1919.
The new law will apply to more than 100 listed companies with employee representatives on the non-executive supervisory board.
Medium-sized businesses will have to publish their gender-equality targets for top jobs.
Chancellor Angela Merkel had initially opposed the reform, which was approved with backing from her conservatives and their junior coalition partners, the Social Democrats (SPD).
The SPD made a women's quota one of its top priorities after agreeing to enter the "grand coalition" with Merkel's bloc in 2013.
Opposition parties abstained in Friday's vote, with the Greens criticising it as a "quota light" for not going far enough.
Criticism also came from the BDA Confederation of German Employers' Associations, which argues that mandatory quotas and targets fail to tackle the root problem.
Steps to help women better manage a career and family should be the focus, it argues.