WASHINGTON (Reuters) – U.S. business inventories increased a bit less than expected in August, but there are signs that unsold goods are piling up at retailers and wholesalers as stubbornly high inflation and rising interest rates slow demand. Business inventories rose 0.8% after climbing 0.5% in July, the Commerce Department said on Friday. Inventories are a key component of gross domestic product. Economists polled by Reuters had forecast inventories advancing 0.9%. Inventories increased 18.2% on a year-on-year basis in August. Retail inventories jumped 1.3% in August instead of 1.4% as esti…