Plans for a major multi-million pound transformation of Union Terrace Gardens in the heart of Aberdeen have been accepted in principle by the local authority.

Businessman Sir Ian Wood has pledged £50m towards the cost of the City Square Project, which has received the backing of Aberdeen City Council (ACC) following a debate into the future of the site. An international design competition is now expected to get underway to advance the £140m project, despite more than half of respondents to a recent consultation opposing the development.

Proposals for Union Terrace Gardens include reclaiming 5 acres (22 hectares) of land by raising the site and covering a dual carriageway, a cultural hub and an outdoor performance stage. Water features that recognise the importance of Aberdeen as a major North Sea port, an amphitheatre and green space are also proposed as part of the development.

ACC leader John Stewart said: "Most people would agree that change is needed in the gardens and across the city centre. Change has to respect the history and architecture of the city - but we have to move with the times and maintain this city as an attractive destination for visitors and new businesses, and as a pleasant place for our citizens." The council confirmed that it would work with Peacock Visual Arts to secure a "sustainable future" for the organisation, which had drawn up alternative plans for the site.