Shares of Frankie & Benny's restaurant chain operator, Restaurant Group rocketed after it said since the end of February it has seen a significant uplift in sales with good growth in March, April and May to date. it is trading in line with expectations and is on track to report a strong first half performance.Trading for the first 19 weeks has been strong with total sales 8% ahead of the previous year and like-for-like sales up 4%. Margins are in line with expectations.During the first 19 weeks the group has opened one new Frankie & Benny's restaurant, two new Garfunkel's and one new Pub restaurant. These sites are trading well and are set to deliver strong returns, it said in a statement. In total its expects to open between 25 and 30 new restaurants this year with a strong pipeline developing for 2013 and beyond. It said the group's balance sheet remains strong and continues to benefit from good cash generation from its operations. CJ