WASHINGTON (Reuters) -U.S. wholesale inventories were unchanged in August as increases in stocks of long-lasting manufactured goods like motor vehicles offset decreases in prescription medication and paper.

The unchanged reading reported by the Commerce Department's Census Bureau on Friday was an upward revision to the 0.2% decline estimated in September. Economists polled by Reuters had expected that estimate would be unrevised. The report was delayed by the recently ended 43-day shutdown of the government.

Inventories, a key part of gross domestic product, edged up 0.1% in July. They increased 1.1% on a year-over-year basis in August. Wholesale stocks of motor vehicles gained 0.4%. There were also increases in inventories of metals, computer equipment and lumber. But prescription medication and paper inventories fell as did stocks of chemicals.   

Business inventories decreased at a $18.3 billion annualized rate in the second quarter, subtracting 3.29 percentage points from GDP. That was, however, more than offset by a record 4.83 percentage point contribution from a smaller trade deficit.

The Atlanta Federal Reserve is forecasting gross domestic product grew at a 4.2% annualized rate in the third quarter. 

The release of the advance third-quarter GDP estimate, initially scheduled at the end of October, was delayed by the longest shutdown in history. The economy grew at a 3.8% pace in the April-June quarter.

Sales at wholesalers ticked up 0.1% in August after accelerating 1.3% in July. At August's sales pace it would take 1.28 months to clear shelves, unchanged from in July.