The operator of the index of leading German companies has announced a raft of new additions as the blue-chip index braces for its biggest ever shakeup.

Carmaker Porsche and sportswear brand Puma are among the beneficiaries of the Dax expanding from 30 to 40 companies in just two weeks’ time.

The expansion of the Dax has been driven by regulators coming under pressure to take steps to improve German listed companies’ corporate governance after the collapse of Wirecard last year.

Increasing the number of companies included on the blue-chip index is intended to improve diversification and provide greater stability for investors.

The changes will come into force on 20 September. Other new entrants include the plane manufacturer Airbus and the online fashion retailer Zalando.

Deutsche Boerse, the Dax’s operator, announced the overhaul plans last November. It has also imposed stricter membership criteria in financial reporting and profitability to avoid future Wirecard-type scandals.