The block chocolate is known as Galaxy in the UK and the Middle East, but goes under the Dove brand in most of Europe and Amicelli in Germany.
The confectionery giant has asked agencies to investigate applying one consistent brand image.
The project is being co-ordinated from Masterfoods UK, with involvement from the other territories. Any conclusion is not likely to be implemented for several months.
Since the late 80s, Galaxy has been positioned as a creamy, smooth milk chocolate and marketed primarily at women with the proposition 'Why have cotton when you can have silk?'
The most recent £5m campaign through Grey/Worldwide London ran in 2000 and transported viewers into a chocolate fantasyland, showing a woman entwined in brown silk and falling through the air onto a bed of autumnal leaves in a forest.
The endline was tweaked to 'Galaxy: Is your chocolate as smooth as silk?'
However the 'silky' concept is not used globally, and Masterfoods is believed to want to fine tune the UK proposition and see whether it will work in other markets. The company is not looking to change its target market, but it is understood to be looking for a new 'purchase trigger' of an emotionally-based reason for consumers to choose the brand.
Since its 1960s launch, Galaxy has been the UK's number two block chocolate bar behind Cadbury's Dairy Milk. However, it now faces new competition with Nestle's decision to enter the market with Double Cream. Nestle aims to spend £34m promoting Double Cream over the next four years.