Specialists from seven teams worked together to help the property development and investment company acquire the famous ITV Granada television studios, in a partnership with Manchester City Council called Manchester Quays Limited.
Members of the national law firm's real estate, planning, litigation, banking, corporate, tax, and environmental teams acted for Allied London.
Its chief executive Mike Ingall said: "We've received fantastic service from Shoosmiths, which far exceeded our expectations. This is a landmark deal that will lead to a major development in the city centre, so it was essential we got it right."
Partner and real estate specialist Vaqas Farooq, who led the Shoosmiths team based in Spinningfields, said: "It was a tremendous cross-team effort. Everyone worked so hard and in such a short timeframe to achieve a great result.
"Manchester Quays has an exciting vision for the site. It's a real sign of confidence in Manchester, and I'm delighted that we're working with them in helping to deliver a significant regeneration project for the city."
Real estate partner Claire Quinn led the Irwin Mitchell team that acted for ITV.
The Allied London-Manchester City Council partnership plans to develop the 13.5 acre former studios site, in Quay Street. Largely vacated by ITV earlier this year, it will become a mixed-use area featuring offices, retail spaces and homes.
Allied London has more than 180 years' combined experience in UK commercial and residential property markets, having managed, invested in and developed millions of square feet of real estate.
In the last 10, years, it has continued to deliver landmark projects across the UK, from delivering a new contact centre cluster for Glasgow, to creating a new 'village' in London, and developing Spinningfields, a major business quarter for Manchester.
ITV Granada has been based in Quay Street since 1956. Its move to Salford's MediaCityUK was announced in December 2010, and the final phase of the relocation is scheduled to happen in early 2014.