Supply chain snags crimping global trade weighed on Japan’s exports last month as auto shipments plunged, weakening a key pillar of the country’s economic recovery.

Growth in Japan’s overseas shipments slowed in September to about half August’s pace, advancing 13% from last year’s level, the Finance Ministry reported Wednesday.

Gains from deliveries of steel and chip components were muted by a drop in the nation’s key car exports. Economists had forecast a slowdown to an overall growth pace of 10.5%. On a seasonally adjusted basis, exports fell 3.9% from the prior month, the first month-on-month drop since February.