Germany's parliament is expected to pass a law requiring some listed companies to have a minimum number of women on their board of directors in an attempt to increase gender equality in the workplace.

After facing some foot-dragging in parliament, the legislation, which the cabinet approved in January, could be passed this summer after the two biggest parties reached an agreement.

"The first quota for management boards is coming. This is an historic breakthrough," Katja Mast, deputy head of the Social Democrats' (SPD) parliamentary group, told Reuters.

The new law affects around 70 companies and will force larger listed firms whose boards have more than three members to include at least one woman on them.

Firms will be required to report on whether and how they aim to meet the quota. They risk a fine for failing to give a good reason for not setting a target to include any women on their management boards.

"Highly qualified women still come up against glass ceilings far too often," said Justice Minister Christine Lambrecht.

"There are still pure men's clubs on the boards of directors who like to keep to themselves. This will come to an end in the future."

The new legislation also creates a legal right for board members to take up to three months of parental leave and time off to care for family members without having to give up their mandate.

A study on Thursday showed that the number of women in German boardrooms was only rising slowly and that many large listed German firms have no women on their management teams.