Grand $700m plans for twin high-rise towers on two prime parcels of Melbourne land previously owned by Crown casino have been approved.

Towers soaring 52 and 25 levels high will be erected in the same block as the casino after Melbourne developer LAS Group got the green light to build 700 homes on one of Southbank's most prominent city addresses.

Redevelopment on the adjoining sites at 101 Clarendon St and 38 Clarke St in Southbank will turn land previously used as warehouses and low-rise office space into towers just a short walk from the casino, South Wharf and Melbourne Aquarium.

LAS Group director and founder Les Smith said the development was a vote of confidence in Melbourne.

“Confidence is starting to return given the recent interest rate drops and the buoyancy the economic climate, so we believe the time is right to bring these new projects to market in the coming months,” he said.

Part of the sale of land for the project included the transfer of development “air rights” above the Crown casino carpark to increase one of the builds' footprints.

The sleek towers, designed by architecture firm Fender Katsalidis, will feature intricate brick masonry and arched windows at street level.

The $511m Clarendon St tower will house 509 apartments with amenities including a lounge, private dining room, podcast room, golf simulator, co-working spaces, pet care facilities and an outdoor terrace. It will be finished by 2029.

The $187m Clarke St building will have 188 apartments, a pool, gym, cold plunge pool and sauna. It will be completed by 2028.