The court also ruled that the Takeovers Panel did not have power to make divestment orders in relation to the August acquisition.

The court is expected to make orders in the coming weeks.

“In its application to the court, APT asked the court to order the disposal of approximately 10% of APT securities acquired in August, as well as part of the parcel acquired from AGL (approximately 5% of APT securities),” APT said in a statement.

“APT is considering what orders it will request the court to make."

APT said the decision vindicates its position taken in response to the actions by Alinta last year.

“I hope that this concludes this matter which has been an unnecessary distraction and waste of resources for all involved,” APT managing director Mick McCormack said.

“APT’s response to Alinta’s actions, including the raid on the register in August, was motivated by our commitment and responsibility to act in the best interests of our security holders.

“As demonstrated by APT’s recent growth, APT will continue to focus on building value for our security holders through bringing together a truly national energy infrastructure business.”

Alinta, which holds about 35% of APT, said it is reviewing the judgement and will consider its legal options over the coming days.

“Altinta does not know whether other parties to the proceedings will appeal the decision,” it said.