The west London-based practice will redesign the dining and 'retail environment' within the Neo-Classical building, which sits next to the city's cathedral.
Founded in 1865, La Rinascente is one of Italy's leading fashion retailers and the Milan outlet is the brand's flagship store.
The firm will again work alongside restaurant consultant Dominic Ford. LDS has already collaborated with Ford on a number of acclaimed top-floor restaurants, including those at the OXO Tower on London's South Bank and at Harvey Nichols in Knightsbridge, Manchester and Edinburgh.
LDS director Paul Sandilands said: 'This project presents a fantastic opportunity to create a new shopping and restaurant facility at the flagship store of one of Italy's foremost fashion retailers and in a most amazing location, with views just waiting to be experienced'.
The scheme will start on site early next year and is due to open in autumn 2006.