UK commercial vehicle (CV) production fell by 57.2% in June, according to the Society of Motor Manufacturers and Traders (SMMT).
Manufacturing for both home and export markets experienced declines in the month, falling 44.7% to 1,715 and 65.4% to 1,630 respectively.
A tally of just 3,345 vans, trucks and buses left production lines last month, as key model changeovers continued to impact output.
In the first six months, output fell 15.8% to 35,130 versus the same period in 2018.
The overall fall was driven by three months of significant decline following a strong start to the year. Home production increased by 11.1% to 15,395 while exports fell 29.2% with 19,735 units shipped abroad in the first half of the year. However, exports still accounted for more than half of all UK CV manufacturing, with the majority destined for the EU.
Mike Hawes, SMMT chief executive, said: "Although model changes and fluctuating fleet buying cycles are behind the recent decline, these half-year results once again demonstrate the importance of exports to UK commercial vehicle production."