The car and aircraft technology company GKN is to make reductions in its workforce, putting jobs in the UK at risk.
Shares in the Redditch-based company fell more than 20% as it said pre-tax profits for the fourth quarter would be "materially below" its mid-year guidance.
"We are now experiencing significant further deterioration in demand in automotive markets globally," GKN said in a statement.
"Our production schedules indicate fourth quarter sales to be around 15% lower than last year with activity levels 20% below those at which we left the first half."
It said it would be shutting down plants, introduce short-time working and reduce its workforce.
It did not specify what they would mean for the 5,000 people who work for GKN in the UK.
About half of these work on the car side of the business, at two plants in Birmingham and another in Telford. The other half work in aerospace.
GKN has been hit by the slowdown in the automotive sector – which has led to the cancellation of a number of projects - and a machinists' strike at the aerospace company Boeing.
Shares were changing hands this morning at 93p – down nearly 21% on Friday night's close, making it the FTSE 250's biggest faller.
Another company feeling the effects of the recession today is the house-builder Persimmon.
The company said unit sales prices were likely to fall 10% in the second half of the year rather than the 5% previously forecast.
However, underlying full-year results should meet forecasts, the group added.
Shares initially slipped 8% to 200p, but have recovered and entered positive territory, currently up 5% at 227p.
Persimmon said the uncertain financial outlook had hit sales across the UK, with cancellation rates at around 35%.
It expects to complete around 10,000 homes this calendar year.
