John Lewis said that department store sales in the week to October 14 increased 15.8 per cent compared with last year.In the 11 week period to October 14, department store sales were up 6.2 per cent on last year. John Lewis' estimate of department store sales for the half-year as a whole is for an increase of 3.8 per cent on 1999-2000. Nigel Brotherton, department stores administration director, said: "The cold, damp weather was undoubtedly in our favour on this occasion, and fortunately the floods seem not to have caused too many difficulties for customers in the areas where we trade."