(Reuters) -Mattel posted a smaller-than-expected loss for the first quarter on Tuesday, helped by the Barbie maker's tight leash on costs while demand remains tepid for its toys. "We are off to a good start for the year with significant margin expansion and very strong improvement in free cash flow," CEO Ynon Kreiz said in an interview with Reuters. Mattel's gross margin grew 8 percentage points to 48% in the first quarter, also in part due to easing input costs as well as lower inventory management expenses.