NEW DELHI: Retail inflation based on consumer price index (CPI) inched up for the fourth consecutive month to 3.9% in May from 3.5% in April on account of acceleration in food prices, data released by NSO on Friday showed. The food index rose 4.8% in May, above 4.2% in the preceding month.Despite the staggered increase in retail fuel prices during the past month in the backdrop of persisting conflict in West Asia, fuel inflation remained contained at 0.8% in May, though marginally higher than 0.7% in April.Economists expect the pass through to become visible in June. Dipti Deshpande, principal economist at Crisil said food inflation rose due to persistent high temperatures, which drove up prices of vegetables, dairy products and eggs.“Part of the estimated 36 basis points (100 basis points equal a percentage point) direct impact on CPI from cumulative Rs 7.5 a litre hike in fuel prices is already visible, with the remaining pass through expected in June,” she said.Core inflation, after stripping out volatile food and fuel components, hovers around 4%.