WASHINGTON (Reuters) - U.S. business inventories fell in April, with stocks declining at a sharper pace than initially estimated amid shortages of raw materials, which are undercutting production of motor vehicles and other goods. Business inventories decreased 0.2% after increasing 0.2% in March, the Commerce Department said on Tuesday. Inventories are a key component of gross domestic product. Economists polled by Reuters had forecast inventories dipping 0.1%. Inventories dropped 3.6% on a year-on-year basis in April. Retail inventories decreased 1.8% in April, rather than 1.6% as estimated in an advance report published last month. That followed a 1.4% decrease in March. Motor vehicle inventories dropped 7.5% rather than 7.0% as estimated in an advance report published last month. Motor vehicle stocks are being run down as a global semiconductor shortage weighs on auto production. Retail inventories excluding autos, which go into the calculation of GDP, increased 0.6% instead of 0.5% as estimated last month. Manufacturers are battling shortages of raw materials and labor in the wake of pent-up demand unleashed by the reopening of the economy as vaccinations ease COVID-19’s intensity. With demand robust, inventories were depleted in the first quarter. The inventory drawdown subtracted nearly three percentage points from GDP growth last quarter. Still, the economy grew at a strong 6.4% annualized rate after expanding at a 4.3% pace in the fourth quarter. Most economists are forecasting double-digit GDP growth in the second quarter. Wholesale inventories increased 0.8% in April. Stocks at manufacturers rose 0.3%. Business sales advanced 0.6% in April after rebounding 5.8% in March. At April’s sales pace, it would take 1.25 months for businesses to clear shelves, down from 1.26 months in March. Reporting by Lucia Mutikani; Editing by Chizu Nomiyama Our Standards: The Thomson Reuters Trust Principles.