Value chain Primark is the first tenant confirmed for Intu Trafford Centre’s £74m extension.
The unit, which is set to open in 2019, will incorporate space previously occupied by BHS Home.
The move marks a significant upsizing for Primark, since it currently operates as a concession on the upper level of Selfridges at the shopping centre.
The 110,000 sq ft expansion at Barton Square will include a new glass-domed roof and fully redesigned interior.
Work on the site is expected to begin during the first half of 2018.
Intu regional managing director Colin Flinn said: “This is a significant milestone for intu Trafford Centre that will enable us to reposition and redevelop an important part of the centre so that we can create even better customer experiences and more opportunities for retailers to flourish.”