Bosch may be about to cut jobs at its car components plant near Cardiff.
The company said it is reviewing the position of its temporary staff at its plant in Pontyclun, which makes alternators.
Reports suggest up to 300 jobs may be affected, blamed on uncertain market conditions.
Bosch said: "Due to the currently difficult market environment, Bosch is expecting a lower production volume for alternators at its Cardiff plant in 2009 than in the present fiscal year."
It employs around 1,400 people at Pontyclun.
The plant was built in 1989 and was Bosch's first in the UK, with production starting in 1991.