U.S. wholesale inventories rose slightly more than initially estimated in December, offering hope that supply chain constraints could be easing.

The Commerce Department said on Wednesday that wholesale inventories increased 2.2% in December, instead of 2.1% as estimated last month. Stocks at wholesalers advanced 1.7% in November.

Economists polled by Reuters had expected inventories would be unrevised. Wholesale inventories jumped 18.5% in December from the year-earlier period.

Inventories are a key part of gross domestic product. The report followed news on Tuesday that goods imports increased to a record high in December.

Strained global supply chains had been making it harder for businesses to replenish depleted inventories. Motor vehicle stocks remain very low because of a global shortage of semiconductors, which is constraining motor vehicle production.

In December, wholesale motor vehicle inventories accelerated 4.6% after rising 3.4% in November.

Wholesale inventories, excluding autos, increased 2.0% in December. This component goes into the calculation of GDP.

Inventory investment surged at a seasonally adjusted annualized rate of $173.5 billion in the fourth quarter, the second-largest quarterly increase on record.

Most economists see further scope for inventories to rise, noting that inflation-adjusted inventories remain below their pre-pandemic level. Sales-to-inventory ratios are also low.

Inventories contributed 4.90 percentage points to the fourth quarter's 6.9% annualized growth pace. Restocking, after three straight quarters during which inventories were drawn down, is supporting manufacturing.

Sales at wholesalers gained 0.2% in December after rising 1.7% in November. At December's sales pace it would take wholesalers 1.25 months to clear shelves, up from 1.22 months in November.