A new 20,000 tonne moulding plant will be built with wrapping and packing lines and an extra chocolate manufacturing area will be constructed to support the moulded plant.
Cadbury Schweppes was unable to confirm the exact date that work would begin. But company spokesman Tony Bilsborough said the work was scheduled to start later this year in order to meet the completion deadline of autumn 2006.
The group was also unable to confirm how many jobs would be created as a result of the expansion.
According to the company, the Cadbury Dairy Milk brand currently commands sales of £320m a year and the brand grew by 10% in 2004.