The Co-Operative chairman Allan Leighton has announced he is joining the board of the Duke Street Capital–backed chain Wagamama.

Leighton will chair the group as it gears up its expansion plans, with a further 40 stores set to be added to its estate in the next three years.

Leighton, who made his name turning around Asda with Archie Norman in the late 1990s, is to join Wagamama’s board this week.

He told the Sunday Times: “We’re in expansion mode. We could easily have a couple of hundred restaurants in the US eventually — that’s the scale of our ambition.”

Since leaving Asda, Leighton has taken on a wide range of jobs, including chairing the Royal Mail from 2002 to 2009. He endured a stormy first annual meeting as chairman of the Co-operative Group in May, when more than a third of the mutual’s members refused to back its reformed pay policies.

In its most recent update, for the 12 weeks to 1 February, Wagamama reported like-for-like sales across its 112-strong UK estate increase 9.9%, with turnover up 18.3% to £47.3m. Adjusted EBITDA for the quarter climbed 14.5% to £7.9m, while net debt fell to £127.1m from £128.8m. For the 40 weeks to 1 February, like-for-like sales climbed 10.5% with adjusted EBITDA increasing from £18.4m to £22.7m. Turnover for the period climbed 19.8% to £147.4m.