Last year, the company spent £25m on advertising, according to Nielsen Media Research, but this figure does not include its £10m-a-year sponsorship of ITV's Coronation Street, which it dropped in September.
It is believed that a significant amount of the increased budget, understood to be more than £30m, is likely to back the relaunch of Cadbury Dairy Milk in March. The size of the chocolate bar will be reduced from 250g to 230g and its packaging will be redesigned.
The relaunch will be supported by the follow-up to the popular 'Gorilla' ad by Fallon London, which will also feature an animal playing an instrument.
Last week, Cadbury agreed to sell Monkhill Confectionery, which makes Barratt's Sherbet Fountain and Butterkist popcorn, to Blackpool sweets group Tangerine for £58m.
Cadbury is on schedule to beat its targets for 2007 after an uplift in UK chocolate sales in the second half of the year.