Jan 9 (Reuters) - Britain's Restaurant Group Plc said turnover rose 9 percent for the year ended Dec. 30 as more people opted to eat out at its casual dining chains rather than high-end restaurants, and it estimated profit to be slightly ahead of market forecasts. The company, which owns the Frankie & Benny's chains, said analysts' average forecast for pretax profit for the 52-week period was 64 million pounds ($103 million).