(Adds details, share reaction, analyst comment)
By Wout Vergauwen
July 27 (Reuters) - Belgian diaper maker Ontex posted a 12.8 percent increase in second-quarter profit on Thursday, but its shares fell after it missed analysts' expectations due to weaker-than-expected demand and rising raw material costs.
Its shares slid 5.1 percent to 29.98 euros ($35.13) at 0718 GMT, making it the top faller on Brussels' BEL 20 index.
Ontex said market growth for its babycare, female-care and adult incontinence categories had been below the full-year forecast for the beginning of the quarter, extending weaker growth seen in the first three months of the year.
Adjusted earnings before interests, taxes, depreciation and amortization (EBITDA) for the April-June quarter was at 74.7 million euros ($87.7 million), up from last year's 66.2 million euros. Analysts polled by Reuters had expected an adjusted EBITDA of 76.7 million euros.
Profit growth lagged revenues over the quarter, pressuring margins, which fell 87 basis points to 12.1 percent.
Chief executive Charles Bouaziz said there was "temporary pressure on our manufacturing and supply chain, which along with rising input costs has contributed to short-term margin pressure."
Ontex also said it expected growth in revenue to outpace growth in its main markets for the full-year 2017. It said prices for its main commodity raw materials would continue to create a headwind for the rest of 2017.
$1 = 0.8534 euros Reporting by Wout Vergauwen; Editing by Sunil Nair