Permira has bought Unison Capital's stake in Akindo Sushiro, a sushi restaurant chain based in Japan, in a deal that values the business at $1bn (€797m). 

Osaka-based Sushiro operates 335 sushi restaurants with revolving counters. Last year it opened its first overseas outlet in South Korea. The company was acquired by Japanese private equity firm Unison Capital in 2007. 

The deal represents Permira's fourth investment in Asia and the second in Japan following the acquisition of agrochemical group Arysta Lifescience in 2008. 

In the year to September 2011, Sushiro generated revenues of JPY100bn (€1.01bn).