Both companies are proposing a merger or takeover followed by a demerger into separate energy and infrastructure entities.

The only substantial difference between the two offers is the preferred management teams. AGL wants its CEO Paul Anthony to head energy and has extended an invitation to Alinta head Bob Browning to lead the infrastructure arm.

But Alinta and Browning insist that he should lead the energy company.

Alinta chairman Tony Howarth admitted that AGL’s offer was “essentially the same” as his own company’s offer. AGL has offered 0.564 AGL shares for each Alinta share, which is a similar ratio to Alinta’s initial proposal of 1.773 Alinta shares for each AGL share.

But he told the ASX last night that the Alinta board believed a merger via a scheme of arrangement, rather than a takeover, delivered better value for shareholders.

Howarth said the AGL proposal also failed to take into account Alinta’s financial and operational results, which have consistently delivered better returns to investors.

But AGL chairman Mark Johnson countered that Alinta had no experience of being a retailer in a broad and competitive market. The West Australian-based company's retail customers are mostly in Perth and are mostly in gas. Alinta has only 1000 electrcity customers.