Mobile phone rebranding confuses consumers and many think O2 and T-Mobile are new firms, according to a study by analysts at Continental research.

Over 90 percent of Orange and Vodafone users recognised branding for their mobile operator, but only 66 percent of T-Mobile customers and a poor 39 percent of O2 customers could do the same.

But both O2 (formerly BT Cellnet) and T-Mobile (nee One2One) have spent thousands on advertising campaigns to promote their new brands.

"As both networks have a customer base in the millions, the way the networks communicate the name change to existing customers is crucial," said James Myring, analyst at Continental Research.

"Phones purchased as BT Cellnet phones still have the Cellnet logo on the display screen [whereas most One2One phone logos have changed]. Also, from my recollection, some of the TV advertising promotes the new brand name, with little or no reference [to the fact] that it used to be called by a different name," said Myring.

Recent campaigns such as O2's Big Brother text messaging service have helped to strengthen the brand name and raise awareness and, according to Myring, in the long run rebranding does work.

"Although people are always reluctant to change, the name changes are logical in order to harmonise [the brand] across Europe. Frequent business travellers are already starting to notice this cross-country branding," added Myring.