A John Lewis store set to close in July could be turned into offices, an event space, restaurants and bars.
Last month the retailer announced its Knight & Lee outlet in Southsea, Hampshire, would close in July after more than 100 years of trading.
Property company That Group has bought the freehold and revealed its preliminary proposals which it said would "breathe new life" into the building.
A consultation runs until 11 March.
That Group previously revamped The Echo building in Bournemouth as office space for This Workspace. It plans to do the same at the Knight & Lee store.
Other options, which are subject to planning permission, include meeting and event spaces, shops, restaurants, cafes and "pop-ups".
The company said: "Our plans represent a multi-million pound regeneration within Southsea's town centre which will rejuvenate and refurbish the Knight & Lee building.
"This will deliver the significant investment required to breathe new life into the building, securing its long-term and viable future."
The Knight & Lee store opened in Southsea in 1865 and was acquired by the John Lewis Partnership in 1933.
It is one of only two John Lewis shops in the UK to retain its original name.
Portsmouth South MP Stephen Morgan previously said the shop was a "well-loved asset" in the area and its closure would "rip the heart out" of Southsea.
The retailer said every effort would be made to find the 127 staff roles in nearby John Lewis and Waitrose stores.