Australian energy supplier AGL Energy has rejected a sweetened A$9bn (€6.1bn) second takeover offer from a consortium led by Brookfield Asset Management.

The consortium, backed by Australian tech entrepreneur Mike Cannon-Brookes lifted their offer by 75 Australian cents per share to A$8.25 from their initial proposal of A$7.50 made a fortnight ago.

In a market update, the AGL board said it considered the revised unsolicited proposal still undervalued the company.

AGL Energy chairman Peter Botten said: “The revised unsolicited proposal continues to ignore the opportunity that AGL Energy shareholders have through our proposed demerger to realise potential future value.

“It also ignores the momentum we have recently seen in the business through our solid half-year result, strong progress on the demerger, strong interest in our Energy Transition Investment Partnership and the improvements we are seeing in forward wholesale prices.”

In a Twitter post, Cannon-Brookes, the co-founder of software developer Atlassian, said it was with great sadness that the consortium was “putting our pens down”.

“This weekend, the board rejected our raised offer of A$8.25 – 46% more than the price of A$5.55 about 90 days ago,” he said.

The consortium’s proposal to spend between A$10bn and A$20bn in large-scale renewable energy and batteries to enable the early closures of AGL’s power stations that account for 8% of Australia’s overall greenhouse gas emissions “would have been the world’s biggest decarbonisation project”, he added.

To read the latest edition of the latest IPE Real Assets magazine click here.