Quilvest, the private equity backer of YO! Sushi, has taken a significant minority stake in Tortilla, the Mexican fast-casual dining concept, which will lead to a substantial rollout of the brand over the next five years, M&C Report has learnt. The private equity group has invested £3.5m in the seven-strong London-based chain, which was founded by managing director Brandon Stephens in Islington in October 2007. The chain has already signed on a deal for its eighth site in the capital in Wimbledon, which will open early next year, and has entered into legal discussions on a ninth unit. It is also understood to be in talks for several additional sites. It is thought that the main focus for the chain in the short-term will be the addition of further sites within London, although it is believed to be looking at opportunities to open its first unit outside the capital. The deal places Tortilla firmly at the forefront of the UK’s fast growing Mexican grill market. Quilvest partner Axelle Strain joins the company’s board of directors whilst Paul Campbell, formerly chief executive of the Clapham House Group, whose Hill Capital Partners fund remains an investor in the chain, becomes a non-executive director. Strain said: “Quilvest has significant experience in the UK and global casual dining segment, particularly through our work with YO! Sushi. Tortilla is a fast growing and ambitious brand, operating in a dynamic market and I am delighted to support the team at such an exciting time in the company’s development.” Stephens said: “We’re very pleased to be partnering with Quilvest, who has a proven track record in the casual-dining space and are a great team with significant resources, to grow Tortilla into the leading fast-casual Mexican restaurant chain in the UK. "And we’re thrilled to be launching our Wimbledon store. It’s a busy area with a good balance of local offices and a vibrant evening scene. The restaurant will look absolutely beautiful and customers should expect the same great offering.” The chain opened its latest site in September at Westfield Stratford. It also operates sites in Canary Wharf, Hammersmith, Leadenhall, Oxford Circus and Southwark. Quilvest acquired YO! Sushi, the fast-casual Japanese restaurant chain, in March 2008 in a deal thought to be worth about £50m. Under Quilvest’s ownership, YO! Sushi has grown its UK estate from 30 sites to 56. It also currently operates 11 franchised sushi bars in Ireland, Portugal and the Middle East. It will open its first site in the US in Washington at the start of next year.