WASHINGTON (MarketWatch) - U.S. producer prices fell a seasonally adjusted 0.4% in April to mark the seventh decline in the last nine months, mainly because of lower gasoline and food costs. Economists polled by MarketWatch had predicted no change in the producer price index after a 0.2% increase in March. The price of goods sank 0.7% in April while services slipped 0.1%. Meanwhile, core producer prices that exclude the volatile categories of food, energy and trade rose 0.1% last month, spurred by a sharp increase in the cost of drugs. Over the past year overall producer prices have fallen a record 1.3% on an unadjusted basis. Yet the core rate has risen 0.7% in the same span, a sign that inflation is not entirely muted.