The first architects tasked with designing the £165m refurbishment of the civic complex around Manchester Town Hall have been chosen.
Ian Simpson Architects has won the tender to design the refurbishment of the Town Hall Extension building while Liverpool-based Ryder Architects will design the refurbishment of the Central Library.
A separate international design competition will be launched in January 2010 for St Peter's Square and Library Walk, the curved walkway between the Town Hall Extension and Central Library. The cenotaph and Metrolink stops will be retained in their current positions in St Peter's Square.
The council said the revamps will start next year and will last up to four years, during which time the council will relocate staff to First Street.
Both buildings are Grade II*-listed and their respective refurbishments will be sympathetic and ensure that listed features are preserved.
Cllr Bernard Priest, executive member for finance and human resources, said: "This is a momentous, once in a lifetime project to preserve these historic buildings while enabling them to deliver top quality services. Having architects with such international reputations on board will undoubtedly help us achieve this. We have chosen their tenders because they provide the best combination of value for money and expertise."
A spokeswoman for Ryder said the appointment followed its award-winning work on Newcastle City Library with developer Kajima Partnerships, completed in March 2009, and a recent commission from Devon County Council for the interior design of six libraries in a joint venture with Radford HMY Group.