Mother will continue to create UK domestic work but there is a chance that another agency's international work will run in parallel in the UK.
This more international approach to advertising, using creative across multiple markets, is already used successfully by Orange's rival mobile operator Vodafone.
An internal global brand team, called Orange World, is spearheading the creative rethink. Orange World has also approached Lowe in Switzerland and a French agency, thought to be BETC Euro RSCG, which handles the Orange account in France.
Orange said the decision to review its advertising strategy was part of a wider initiative to develop a more consistent approach to the way all of its operations work in Europe. It is in the process of reviewing its media across Europe.
An Orange spokesman said: "We can confirm that we are investigating the possibility of developing consistent creative across more than one country and we will be looking at creative work from some of our incumbent agencies before determining what campaigns we will run later this year.
"This is not a pitch for a global agency and communication functions remain the responsibility of the local markets. However, where it is beneficial to do so, we may consider running consistent campaigns developed by our incumbent agencies."
If the new strategy proves successful, it is understood Orange will modify the type of creative brief it issues to roster agencies.
Country-specific campaigns, such as Orange UK's latest price-led advertising called "fair", would continue to be handled by local agencies, while high-level multimarket brand work and major customer propositions that are relevant in multiple markets would use advertising campaigns developed to run on a regional basis.
Orange's new chief executive, Solomon Trujillo, is behind the drive to adopt an international approach to advertising. He was appointed to head the company in February, following a protracted battle to find a replacement for Jean-Francois Pontal.
Trujillo had been a board member of Orange since 2001 and has spent much of his career in telecoms.
Orange UK's "fair" campaign, its fourth this year, has conspicuously eschewed TV in favour of press and outdoor work. It replaced the previous "learn" creative.