Charter Hall Group is the party behind the purchase of 19.9% stake in the ASX-listed Australian Unity Office, which owns a A$640m (€398m) portfolio, according to sources.

Broker JP Morgan bought the shares after the market closed today and said the acquisition was for a strategic buyer, who was considering making an offer for Australian Unity.

In a term sheet sent to investors, the buyer said it was offering A$2.95 per share, a 6.1% premium to the company’s last closing price.

Australian Unity was a takeover target of Starwood Capital six months ago. 

Starwood Capital made a non-binding offer to acquire all Australian Unity units at A$2.95 per security last October. Then in November, the US investor revised downwards its offer to A$2.87 per security, at which point, Australian Unity rejected its bid.

JP Morgan said the buyer may seek to enter into talks with Australian Unity’s responsible entity in relation to a control transaction of the trust.

When approached by IPE Real Assets, a source involved with Charter Hall said: “No comment,” but hinted that there would be “an announcement tomorrow”.

Charter Hall’s last takeover of a listed company was Folkestone, a small Sydney-based property fund manager, in August last year.

Australian Unity owns nine office buildings in South Australia, NSW, Queensland, Victoria and the Australian Capital Territory, valued at A$641m at the end of last year.