JPMorgan has been in the market buying shares in AGL Energy on Tuesday on behalf of Mike Cannon-Brookes.
It is understood that a line of 33.4 million shares were crossed at $8.75, equivalent to 5 per cent of the company.
The amount equates to $292m.
Mr Cannon-Brookes had earlier secured 11.3 per cent of shares in AGL through a JPMorgan-held derivative.
The owners of the stock have the right to take back the shares to vote on AGL’s demerger plans before June 30.
While the move suggested that the Atlassian co-founder could be increasing his interest, sources say the movement of shares was part of the earlier deal.
His move comes as part of an attempt to block AGL Energy’s demerger of its coal unit.
Origin, Goodman ponder demergers, spin-offs
Two listed powerhouses, Origin Energy and Goodman Group, could both have their sights on major demergers or spin-offs of units in the coming years.
BlueScope management could be Whyalla first step
A move by BlueScope to manage the Whyalla steelworks on behalf of the government could be stage one of a long-term plan to find a solution for the troublesome operation, sources say.