Vonovia is to acquire Austrian residential property group Conwert Immobilien in a deal valuing the latter at nearly one-quarter above its current market capitalisation.

In a statement, the companies said the so-called business-combination agreement would see the merged company in charge of a total of 365,500 residential units, of which 340,000, worth an estimated €24bn, currently belong to Vonovia and are exclusively in German cities.

Conwert’s smaller portfolio will expand Vonovia’s presence in a number of German cities, including Berlin, Potsdam and Leipzig, but also give it a foothold in Vienna, where Conwert will retain its headquarters if the deal is approved.

According to the agreement, shareholders will be offered 179 Conwert shares in exchange for 74 shares in Vonovia – equating to an offer price of €17.58, or 23.8% above Conwert’s six-month average trading price on the Viennese stock exchange.

Rolf Buch, Vonovia’s chief executive, said the agreement was a “great opportunity” for his company to expand its presence in a number of regions and cities.

“We are therefore making an attractive offer to Conwert shareholders and invite them to join our success story,” he said.

Alexander Proschofsky, chairman of the Conwert administrative board, said he intended to accept the offer and tender his company’s shares, recommending other stakeholders do the same.

Conwert’s administrative board has stated it will resign if the takeover is successful, allowing Vonovia to then appoint a majority of its new members.

The companies hope the deal will see savings of €12m from operational and other financial synergies.

The agreement is the latest to boost Vonovia’s residential portfolio after its takeover of Gagfah in 2014 doubled property assets