River Island is doubling the size of its store in Centre:MK in Milton Keynes.
The extension will bring the store at 23-25 Acorn Walk to 20,000 sq ft. It will open before Christmas.
To accommodate the expansion, HMV has been relocated to 86-88 Midsummer Arcade.
Josie Cartridge, customer director at River Island, said: “Centre:MK is a longstanding, top-performing location for River Island and increasing our presence here is a key step in our ongoing growth.”