"Making use of female talent will improve performance," she said. "Women mean business."
As of 2016, she said, companies where men make up less than 40 percent of the board would have to give preference to qualified women over equally qualified men to fill any vacancies, or face penalties. The penalty would also apply if there were too few men on the board.
Individual EU countries would set the penalties, possibly including fines or the annulment of the appointment of a male board member. But the law, if it is approved also by the European Council and the European Parliament, would require those national penalties to be "effective and dissuasive." If they did not meet that test, Reding said, the Commission could institute legal proceedings against the country involved.
At present, women make up 15 percent of the board membership of listed European companies, even though they make up 60 percent of the university graduates.
"This is a waste of talent," Reding said.
The European Commission cited a 2012 Credit Suisse study showing that companies with at least one female board member outperformed those with no women in terms of share price performance.
Olli Rehn, the EU's monetary affairs commissioner, appeared with Reding at the announcement Friday to underscore the Commission's assertion that more women on boards makes economic sense.
"There is a clear economic and business case to have more women in business leadership," Rehn said.
Don Melvin can be reached at http://twitter.com/DonMelvin .