An official opening ceremony was held to mark completion of the public realm at Exchange Greengate on the edge of Manchester city centre and Salford on Thursday.
Salford City Council and partners Ask Developments and Network Rail hope the £13m publicly funded Greengate Square will act as the catalyst to £400m of private investment in the 1m sq ft office and 1,000-unit residential development.
Ask Developments is in advanced talks with Carillion over a joint venture on the first office building at the scheme which will provide 180,000 sq ft and cost £50m to build. The pair is confident of starting construction later this year.
The new square designed by Whitelaw Turkington and Arup is designed to host concerts and markets and is linked to Manchester's Deansgate by a new bridge. There are 36 coloured fountains which can be programmed to suit different activities in the square.
Salford City Mayor Ian Stewart said: "The opening of this magnificent square is just the first step in regenerating the historic Greengate area, bringing huge investment and jobs for the people of Salford.
"Greengate Square will be an icon of our proud city and a central point for creativity as it kick-starts commercial activity in the area."
Greengate Square was funded with £8.5m from the Homes & Communities Agency, £3.4m from the North West Development Agency and £1.38m from the European Regional Development Fund.