The AUD4.1bn (€2.73bn) wholesale Investa Commercial Property Fund (ICPF) has increased its stake in the listed Investa Office Fund (IOF) to 10.03%, making it the single largest shareholder.

Its total holding of 60 million units is valued at AUD265m.

ICPF said its latest investment demonstrates an ongoing commitment and alignment to IOF unitholders.

In a series of recent on-market purchases, ICPF acquired a further 5.5 million IOF shares for AUD25m, adding to an initial 8.94% holding it acquired from Morgan Stanley for more than AUD232m last November.

ICPF and IOF jointly own some of Australia’s best-known premium office towers.

Until now, Cromwell Property Group, which acquired a 9.8% stake in the office trust last April to frustrate a takeover bid for IOF by Dexus, was the single-largest IOF shareholder.

Cromwell also prevented IOF’s planned purchase of 50% of management rights to the trust, currently fully owned by ICPF.

Some stock analysts believe Cromwell could relinquish its holding in IOF as it appears unable to proceed with a takeover.

After ramping up its bid for IOF late last year, Cromwell has since gone quiet, leading to speculation that it has run into obstacles, possibly in funding a AUD3bn takeover of the listed trust.

During a results presentation last month, Paul Weightman, Cromwell’s CEO, said he was considering his options: sell the stake, do nothing or mount a hostile takeover.

IOF triggered a buy-back programme recently and has so far bought 12 million shares, equivalent to 2% of units on issue, for AUD55m.