Volkswagen is still considering a possible initial public offering of its luxury brand Porsche as a way to fund its costly shift towards software and electric vehicles, Reuters sources have said.

The sources added speculation about a Porsche listing, which could be a record-breaking IPO, had surfaced over the year, but no decision had been made due to a complex stakeholder arrangement. It was unclear whether a listing would happen.

Reuters noted reports about a possible listing of the unit have included estimates of a standalone Porsche AG valuation of between EUR45bn and EUR90bn euros (US$101bn).

Earlier, Reuters said, Handelsblatt reported the Porsche and Piech families, who control Volkswagen’s largest shareholder Porsche SE, were considering selling part of their VW stake to fund a substantial stake purchase in a possible Porsche IPO.

The families, who own 31.4% of Volkswagen shares and have 53.3% of voting rights via Porsche SE, could sell enough shares to raise roughly EUR15bn, the German newspaper said, according to Reuters.

They would remain the largest shareholder in Volkswagen, Handelsblatt added, ahead of the state of Lower Saxony, which holds a 11.8% equity stake and 20% of voting rights.

Porsche SE called the report “pure speculation”, without giving further comment to Reuters and Volkswagen declined to comment.

People familiar with the matter had told Reuters last May the families were prepared to take a direct stake in Porsche AG should the luxury carmaker be listed separately.