British retail sales rose by a stronger-than-expected 0.5% in August, helped by sunny weather, but sales growth in July was revised slightly down, official figures showed. Economists polled by Reuters had mostly expected that retail sales volumes would increase by 0.3%. The Office for National Statistics said sales volumes in July rose by a revised 0.5%, down from a previous estimate of a 0.6% month-on-month increase. Compared with a year ago, sales volumes were 0.7% higher. ADVERTISEMENTThree-Month SalesHowever, retail sales fell 0.1% in the three months to August, but at a slower rate than the 0.6% drop in the three months to July.