The appeal follows a rejection of the proposed acquisition by the Australian Competition & Consumer Commission on March 4.

The tribunal has a three-month period to consider the application, with an option to extend up to six months if it decides the matter can’t be dealt with in three.

The independent body sits with a Federal Court judge and two lay members.

“We have decided to seek to have the matter heard by the tribunal rather than the Federal

Court because the legislated timeframe for decision making by the tribunal is shorter than

the time it would normally take the court to consider a matter of this nature,” AGL managing director Michael Fraser said.

The ACCC determined that the proposed acquisition would likely result in a significant reduction in hedge market liquidity and the supply of competitively priced and appropriately customised hedge contracts to second tier retailers.

If the acquisition were to occur, AGL would become the largest generator in NSW, Victoria and South Australia, owning 70-80% of electricity generation when combined with the other two largest retailers, Origin Energy and Energy Australia.

The key assets of MacGen are its Bayswater and Liddell power stations, which together account for 27% of NSW capacity.