Trinistar Manchester, a joint venture between Starwood Capital and Trinity Investment Management, has submitted a planning application to refurbish the 280,000 sq ft historic Royal Exchange.
The grade two-listed building in St Ann's Square is made up of a theatre, 100,000 sq ft of retail accommodation and 120,000 sq ft of offices. The application includes proposals to remodel the office space, reception area and create a roof garden.
Work over the coming months includes an upgrade of the retail units around the building, the theatre and the arcade linking St Ann's Square to Cross Street as well as the introduction of new brands.
Starwood acquired the building in April 2014 for £45m from long-standing owner M&G Real Estate, formerly PRUPIM.
Quintain Estates & Developments had a lease on the Royal Exchange Arcade, which it surrendered to Trinistar at the end of last year allowing plans for the retail units to move to the next stage.
Occupiers in Royal Exchange include Molton Brown, Starbucks, Place North West and engineer Hoare Lea.
Starwood has appointed a project team on the building which includes office agent Canning O'Neill, Tushingham & Moore, MMX Retail, architect Corstorphine & Wright, interior designer Space Invader and project manager 2110 Consult.
Richard O'Boyle, executive director at Trinity said: "As one of the city's cornerstones it's crucial that the Royal Exchange, a building of such stature and cultural importance, is well looked after. This investment will bring the scheme into the 21st Century and will ensure that it retains its appeal from shoppers, theatre-goers and businesses alike."
James Dickinson, director at Canning O'Neill, said: "This building is a true mixed-use scheme and forms an integral part of Manchester's tapestry. Starwood acquired the Royal Exchange last year with the clear objective of realising its potential.
"The scheme itself will benefit from the highest quality finishes with a luxurious boutique feel to the ground floor reception areas."
If approved works would start in July this year with completion scheduled for winter 2016.