Chipotle Mexican Grill, the US-based burrito concept, has reported a 9% increase in second quarter profit to $50.7m (£31.4m), despite margins being impacted by higher food costs. Revenue jumped 10% to $571.6m, as increased traffic led sales at restaurants open at least a year to rise 10%. The group, which was founded by chief executive Steve Ells, opened 39 restaurants during the quarter, bringing its total restaurant count to 1,131. It expects to open between 135 and 145 in 2011. The company said that restaurant level operating margin was 25.8% in the quarter, a decrease of 110 basis points over the prior year period. It said the decrease was primarily driven by “food cost inflation partially offset by leverage from comparable restaurant sales growth”. The group said that revenue for the first six months of 2011 stood at $1.08bn, up 23.3% on the previous year. It said that the growth in revenue was the result of an 11.1% increase in comparable restaurant sales, which was primarily driven by increased traffic during the period. The company opened its first site in the UK in Charing Cross Road last May, and will a second unit in Baker Street later this year. The Mexican food fast casual brand has hired the property agent Michael Peddar & Co to search for sites in London and elsewhere, with a view to opening 200 stores in the UK eventually. It will open its first site in Paris this summer, and is also looking at opportunities in Germany. Steve Ells, founder, chairman and co-chief executive of Chipotle, said: "We are continuing to focus on our efforts to serve better tasting food, made with ingredients from more sustainable sources, and on building a people culture that delights our customers and allows us to develop the future leaders we will need to support our growth. “In spite of some cost challenges during the quarter, we continue to believe that our relentless focus on these things, which really drive our business, will allow us to produce great results for our shareholders over the long term.”