The Birmingham company, which last week marked three years as Virgin Mobile's UK handset partner, is planning an international marketing campaign next year.
While the campaign budget is yet to be finalised, it will mark Sendo's biggest attempt to establish itself as a consumer brand. It will position itself as being at the cutting edge of mobile technology.
A Sendo spokeswoman said: "What we want is to get people to recognise that we are synonymous with technology and something that represents a difference to our competitors."
She added that a launch date for the campaign had yet to be decided, but said: "We have always had plans to do something with the Sendo brand in the long term".
Sendo believes a major brand campaign will bolster its market share by positioning its name at the front of consumers' minds when they are looking for a phone.
Mark Dorbar, Sendo's marketing director, oversaw the appointment of Mustoes.
The company said it would continue to work on projects with Burkitt DDB, which it hired in 2001 for a brand awareness assignment.
Sendo was founded in August 1999 by a team including Philips executive Hugh Brogan as its chief executive.
It supplies mobile phones on an exclusive basis to 27 network operators in 30 countries and has offices in North America, Singapore, Italy, France, Spain, Germany and the Netherlands.
Sendo claims to offer a point of difference because it supplies network operators with products offering extensive customisation potential. Sales this year are expected to exceed £125m, according to recent forecasts.
The company has recently been involved in a legal dispute with Microsoft.
The problem arose last year over a technological partnership that turned sour. A ruling is expected from a US court imminently.
Last month, Sendo abandoned a patent action against Orange over the design of one of Orange's handsets.