WASHINGTON, March 13 (Reuters) - New orders for key U.S.-manufactured capital goods were unexpectedly unchanged in January and shipments of these products fell, pointing to weakness in business spending on equipment early in the first quarter.

The flat reading in non-defense capital goods orders excluding aircraft, a closely watched proxy for business spending, followed an unrevised 0.8% increase in December, the Commerce Department's Census Bureau said on Friday.

Economists polled by Reuters had forecast these so-called core capital goods orders rising 0.5%. Shipments of core capital goods fell 0.1% after increasing 1.0% in December.

The Census Bureau is still catching up on data releases following delays caused by last year's government shutdown.

Business spending on equipment slowed in the fourth quarter. Despite the weak start to the first quarter, equipment investment could pick up amid increased spending on artificial intelligence and the construction of data centers.

The government reported on Thursday that imports of capital goods rose to a record high, driven by computers and telecommunications equipment. Business spending on AI and data center construction is helping to support some segments of manufacturing, which has been constrained by import tariffs.

The U.S. Supreme Court struck down President Donald Trump's sweeping tariffs, which he pursued under a law meant for use in national emergencies. But Trump responded to the ruling by imposing a 10% global tariff, which he said would rise to 15%.

The Trump administration said on Wednesday it was launching two trade investigations into excess industrial capacity in 16 major trading ​partners and into forced labor. Manufacturing has lost 100,000 jobs since January 2025, despite the protectionist trade policy. The U.S.-Israeli war against Iran, which has raised oil prices, could hamper manufacturing.

Orders for durable goods, items ranging from toasters to aircraft meant to last three years or more, were also unchanged in January after falling 0.9% in December.