WASHINGTON — U.S. orders for big-ticket manufactured goods dropped unexpectedly in April for the first time in 11 months, pulled down by plunging orders for cars and auto parts.

The Commerce Department reported today that orders for factory goods meant to last at least three years fell 1.3% in April after rising 1.3% in March. Transportation orders skidded 6.7%. Excluding transportation, which can be volatile from month to month, durable goods orders were up 1% in April.

Factories have been hamstrung by a shortage of supplies as the U.S. economy reopens from the COVID-19 pandemic and demand for goods and services rebounds rapidly. Orders for auto parts, disrupted by a shortage of computer chips, dropped 6.2% in April. Orders for military aircraft and aviation parts fell 8.5%.

A category that tracks business investment — orders for nondefense capital goods excluding aircraft — increased 2.3% last month on top of a 1.6% gain in March.