The deal will support Rhubarb's ongoing growth with the aim of doubling the size of the group's portfolio in the next four years.
It marks Livingbridge’s third entry in to the food and drink sector, following investments in Pho in 2012 and Bistrot Pierre in 2015.
Rhubarb’s contracts include the Goodwood Estate, the Royal Albert Hall and Sky Garden in London’s Walkie Talkie tower.
Michelin chef Heston Blumenthal began a partnership with the group in 2011 and has developed dishes for the company.
ECI acquired a £12m minority state in Rhubarb in 2012, in a deal valuing the business at an estimated £30m.
Benoit Broch, director at Livingbridge said: “[Rhubarb] have long-term contracts at some fantastic locations and a strong pipeline of future growth opportunities and we are very much looking forward to helping them expand their offering both throughout the UK and overseas.”
Rhubarb CEO PB Jacobse added that the group was confident about future growth and was ‘ideally positioned to benefit from positive market trends and current consumer tastes’.
Richard Prosser, who has private equity expertise within the global leisure, travel and tourism industries, will be joining as chairman on completion of the deal.
Rhubarb is also set to open a flagship restaurant at the revived Centre Point building above Oxford Street in late-2017.