LONDON (AFX) - The John Lewis Partnership said in the week to Aug 25 sales in its department stores increased 5.8 pct compared to last year, while sales at its Waitrose food chain were up 6.8 pct. Total sales increased 6.1 pct. John Lewis said department store sales in the four weeks to Aug 25 were up 7.3 pct, food sales were up 6.7 pct and total sales increased 6.9 pct. The group's estimate of department store sales for the half-year as a whole is for an increase of 9.4 pct on 2000-2001, with food up 4.5 pct and total sales up 7.0 pct. Gareth Thomas, director of selling and customer services for the department stores, said the searing temperatures of last Saturday in the south of England -- which saw a shortfall on sales of close on 10 pct for the day -- took the division below estimate for the whole week. Nine branches failed to match last year's sales, although no fewer than seven put on double-figure percentage gains. At Waitrose, the long Bank holiday weekend stimulated sales of fresh and barbecue foods and drinks. As a result, the supermarkets beat estimates and last year's sales comfortably.