The six teams tasked with transforming Aberdeen's Union Terrace Gardens into a new £140m "civic heart" for the city have been unveiled.

Among the front-runners are the designers of the new World Trade Centre, London's iconic Gherkin skyscraper and the Diana, Princess of Wales Memorial in Hyde Park.

The controversial City Gardens Project, backed by a £50m donation from oil tycoon Sir Ian Wood and Aberdeen City and Shire Economic Future (Acsef), has divided opinion with some quarters wishing to preserve the sunken Victorian gardens in its current state.

On Friday, a panel of local business leaders, architects and councillors announced the six design teams who will draft their vision to raise the gardens to create a modern, "vibrant" focal point for the city comprising of several acres of green space and a modern arts centre.

The six finalists now have two months to finish their designs before they are revealed to the public in September.

Included in the second stage of the competition are:

• Diller Scofidio and Renfro (New York) / Keppie Design (Glasgow) working in association with landscape architect Olin Studio.
• Foster & Partners (London) / Vladimir Djurovic Landscape Architecture (Beirut) working in association with cost and construction consultant Gardiner & Theobald
• Snøhetta (Oslo) / Gareth Hoskins Architects (Edinburgh) working in association with engineering and multi-discipline company AECOM
• Gustafson Porter (London) / Niall McLaughlin Architects (London) working with urban analyst Space Syntax, engineer Arup and cost adviser Jackson Coles
• Mecanoo Architecten (Delft, Netherlands) / Cooper Cromar (Glasgow) working in association with landscape architect Ian White, engineer Buro Happold and cost adviser Davis Langdon (AECOM).
• West 8 urban design & landscape architecture (Rotterdam, Netherlands) / Archial Group (Aberdeen) working in association with engineer Arup and cost and construction consultant Turner & Townsend.

Among the homegrown and international teams involved are Fosters and Partners, the firm behind the new Wembley Stadium, the Gherkin at 30 St Mary Axe and the restoration of the German parliament, the Reichstag. They are also in the process of planning one of the new World Trade Centre in New York.

Another of the selected teams is Gustafson Porter, which designed the Diana, Princess of Wales Memorial and a city square at Evry, near Paris.

Sir Duncan Rice, former principal of the University of Aberdeen who chaired the jury panel, said: “That the competition attracted high-level interest from around the world is a great compliment to Aberdeen City and Shire.

"The jury agreed unanimously on the six finalists and is excited about the potential of their visions for the City Gardens Project.”

The International Design Competition attracted 55 submissions from around the globe – involving in excess of 150 companies - received by contest organisers Malcolm Reading Consultants.

Mr Reading added: “The sheer calibre of the finalists’ submissions was exceptional. At this stage of the competition we are selecting on capability and expertise.

"All of the finalists had assembled teams which draw in other skillsets and were able to demonstrate directly relevant experience of handling similar challenges around the world."

Criticism

However, the news was not welcomed by everyone, with some councillors and campaigners accusing the City Gardens project group of ignoring public opinion.

Mike Shepherd, Chairman of the Friends of Union Terrace Gardens, said: “Nobody elected them. What gives a self-selected group the right to decide what the centre of Aberdeen should look like? The public were asked, it is our decision that should be honoured.

“The Scottish Government could feasibly call in the plans and make their own decision on the matter before they are submitted for planning consent to the council. If this happens, there will have been no local democratic audit of the function of an area of land in the city centre that many in Aberdeen care passionately about. The council are letting down the people of Aberdeen.”

Aberdeen City Councillor Martin Greig said: "The consultation on the Ian Wood vision showed that the people do not want the park replaced by a building.

"The two-and-a-half acres within the proposed new construction is a lot of empty internal space that is now in search of a purpose. It has been made clear that the project will still need public money in order to be achieved.

"This is not where the Council intends to spend any money so the project still has a lot of obstacles to overcome. It would be preferable if the whole project could simply be abandoned so that no further time or money is wasted."

A public exhibition of the designs will be held in September and the winning team will be revealed in December. At that stage the council could hold a public referendum to decide if the project should proceed.