WASHINGTON, Sept 17 (Reuters) - U.S. retail sales unexpectedly rose in August as a decline in receipts at auto dealerships was more than offset by strength in online purchases, suggesting that the economy remained on solid footing through much of the third quarter.

Key Takeaways Retail sales increased by 0.1% in August, bucking economist projections of a decline but slowing down from July’s pace.The sales report is the last major release before the Federal Reserve's policy-setting committee makes an interest rate decision on Wednesday.

Retail sales edged up by 0.1% from July to August, according to the Commerce Department. This modest increase follows a larger surge last month, which marked the highest growth rate in retail sales in a year and a half.