Competing restaurants Euro and Soul Bar and Bistro will soon be under the same management.
Nourish Group, which owns Euro, has purchased Soul for an undisclosed sum, with Nourish set to take over on March 1.
Founder of Soul, Judith Tabron, who is staying on for 90 days after the official handover date, said she was leaving the restaurant in good hands.
"I'm very proud of what I've achieved at Soul, but the time seems right to pass on the mantle, and I'm confident that it has found the best possible home with the Nourish Group."
Soul will join a stable of Nourish businesses including Auckland's Euro and Jervois Steak House, and Wellington's Shed 5 and Pravda Cafe & Grill.
The deal marks a full circle for former My Kitchen Rules judge and chef Gareth Stewart, who left Soul to work as executive chef at Nourish in 2015. Stewart will now oversee Soul as well as the other Nourish Group restaurants.
During his almost eight years as executive chef for Soul, Stewart won numerous accolades, including Best Casual Dining at the 2009 and 2010 Cuisine Restaurant of the Year Awards.
Nourish Group said the acquisition meant it was well placed to make the most of both tourist and local diners in the Viaduct area, particularly looking ahead to the America's Cup which would be held in Auckland in 2021.
Group chief executive Richard Sigley said he was thrilled.
"Soul has long been one of Auckland's top restaurants, and we're looking forward to it continuing its reign. We have three fantastic restaurants on Princes Wharf and adding Soul to the group means we can serve even more diners on the city's waterfront."
Founded in 2001, Soul Bar was well known for its seafood dishes and location on the harbour, with celebrities including Beyonce and Jay-Z dining there over the years.
The business was co-owned by Tabron and Eric Watson's investement company Cullen Investments.
Sigley said it would be business as usual for Soul, saying over the past 17 years, Tabron had created a strong team and business that would continue under Nourish Group.
The deal was brokered by Bayleys' Paul Dixon and Carolyn Hanson.