The latest in a series of setbacks for struggling Adler triggered a margin call at Aggregate Holdings, allowing Vonovia to step in and snap up a 20.5% stake in Adler.

Aggregate's exit is likely to compound Adler's problems, just months after short-seller Viceroy Research published a damning report that pushed down shares and raised concerns over Adler's financial future. Following this, Vonovia agreed a €250 mln loan with Aggregate.

However, Adler's recent announcement that a KPGM report analysing the Viceroy findings would delay full-year results, and the resignation of a long-standing board member pushed share prices close to a record low, less than €10 per share. This in turn, according to Vonovia, triggered the loan breach, as 'the shares had been pledged as collateral for a loan that Vonovia had granted to Aggregate'.

Aggregate hit back against the allegations that it had breached loan conditions, and said it was evaluating legal implications. In a statement the firm said that 'it does not believe that this specific event constitutes a cross-default in the Aggregate 2025 bonds, as the Adler shares were not held in a material subsidiary."

The outcome depends on anti-trust clearance. Vonovia clarified in any case that it 'retains all options, including the full or partial sale of the shares'.