The National Trust says the historic Sydney GPO building is “not being protected” after Australia Post finalised the sale to a foreign business venture operated by two Singaporean billionaires.
Federal Environment Minister Josh Frydenberg signed off on the heritage management plan this week, paving the way for the sale of the sandstone building in Martin Place to be finalised.
A joint venture between Far East Organisation and Sino Land Company paid about $150 million for the iconic building.
The venture already held a 99-year lease on the site and owns the adjoining Westin Hotel.
Australia Post moved to appease critics by seeking National Heritage listing for the building to "reinforce existing heritage protections".
"From the very outset of this sale process protection of the heritage value of the Sydney GPO has been foremost in our approach," Australia Post general manager of property Adam Treffry said on Wednesday.
But the National Trust had called for Mr Frydenberg and Prime Minister Malcolm Turnbull to intervene to stop the sale. NSW National Trust chief executive Brian Scarsbrick labelled the secretive sale a national disgrace.
"Along with Martin Place and the Cenotaph (the GPO) gives a real ambience to Sydney, a grandeur," he told 2GB on Thursday.
"To be sold outright to an overseas developer means that it's not being protected at all.
"There's nothing stopping it being onsold by the developer."
The original section of the Sydney GPO - designed by colonial architect James Barnet - opened in 1874 and was the centre of the NSW postage system until 1996, according to the National Archives.
Far East has invested more than $2 billion in partnerships and acquisitions in prime Australian locations since 2013, according to its website.
"With its attractive urban centres, developed economy, well-regulated business environment and stable market conditions, Australia presents an attractive market for Far East Organisation to build a diversified, balanced real estate portfolio," the real estate company says.