Dowlais Group PLC (LSE:DWL) shares fell 6% to 72.35p after the automobile parts maker lowered its outlook for this year.
The company gave a mixed update for the four-month period to 30 April, where revenue was £1.7 billion, down 1.9% on the previous year.
Driveline, Powder Metallurgy and China joint venture all were up, but more than offset by weakness in the ePowertrain product group of the GKN Auto arm.
The FTSE 250-listed group said the decline of the ePowertrain segment, representing around a fifth of GKN Auto sales, was largely driven by increased volatility in battery electric vehicle (BEV) production volumes.
Dowlais said it was encouraged that, despite market volatility, adjusted operating margins of 6.1% in the period were up 30 basis points over the same period of the prior year, with margin expansion achieved in both Automotive and Powder Metallurgy.
Management felt the group had started the year "broadly in line" with expectations but while the wider industry is forecast to see an improvement in the second half "some uncertainty remains".
As a result, full-year revenue is expected to be "slightly below prior year at constant currency" compared to flat guidance before, with performance now expected to be more weighted to the second half, though the group is still confident of expanding operating margin and growing free cash flow this year.
Broker Peel Hunt said it was "a decent performance", adding that ePowertrain reflects the reorganisation of carmaker EV plans in Europe, "where the supply chain has seen big swings up in anticipation of follow-through last year, and then significant reassessment this year".