The sale price remains undisclosed, but it is thought that Duke Street will pay around £215m for the chain. The transaction is expected to close within the next 30 days.
Buyout group Duke Street said it has ambitious growth plans for the Japanese-style chain, particularly in international markets.
“Wagamama has the potential, with additional funding and operational expertise from Duke Street, to extend its category leadership in the UK and accelerate its plans for international expansion,” said Duke Street partner John Harper.
“We are investing in what is already a very strong business and look forward to working with the management team to unlock further value.”
Founded in 1992, Wagamama currently has 70 sites in the UK, three in the US, and a franchise operation with 36 restaurants in 16 countries across Europe, the Middle East and Australasia.
Lion Capital, which bought Wagamama for around £100m in 2005, said it has helped meet the chain’s expansion potential over the past six years.
“Under our ownership, Wagamama more than doubled the number of restaurants in the UK, successfully entered the US with the opening of three sites in Boston and added nine new franchise partnerships and 25 new restaurants around the world. We wish both the management team and Duke Street continued success with the business,” said Lyndon Lea, partner of Lion Capital.
Financing for the acquisition was provided by GE Capital, Investec and Lloyds who arranged and underwrote a senior secured debt package, as well as working capital and capex facilities to support the continued roll out of new restaurants.
Hutton Collins, which has invested in Wagamama on two previous occasions, provided a combination of mezzanine and equity financing as part of the debt finance.
Wagamama chief executive Steve Hill said: “We have enjoyed working with Lion over the past six years.
“Thanks to the continued dedication of the Wagamama teams throughout the world, we have achieved some great results over this period and further expanded the Wagamama brand both in the UK and abroad.
“We are all very excited about the future and look forward to working with Duke Street, which will see Wagamama through its next stage of growth.”