The UK's most popular mobile network is drawing up a shortlist of agencies in a review overseen by Jeremy Dale, its new brand marketing director.
Dale said there would be a competitive pitch. "I want to reinvigorate the brand and give it the stand-out that it had in its early days."
The relationship between Orange and Lowe is understood to have been rocky for some time. It is thought to have come to a head last week with the resignation of Lowe board account director Sarah Gold, who is leaving to join Clemmow Hornby Inge.
Chris Thomas, chief executive at Lowe, said: "In the past few months there has been a number of issues on both sides of the relationship and there has not been a meeting of minds. For the health of the agency and the benefit of the rest of our clients it was right to call time on our relationship with Orange by giving notice."
Two weeks ago, former ITV Digital marketer Dale firmly denied rumours that Orange was talking to other agencies. The day after joining Orange on August 19, he told Marketing: "My priority is sorting out the team. There is no way I would look at reviewing agencies without getting my feet under the table first."
Orange said it was drawing up a shortlist of agencies and would "continue to work closely with Lowe until a new agency was appointed". Media, through Media Planning Group, is unaffected.
Lowe won the Orange account in 2000 after it reviewed the business out of launch agency WCRS. At the time, Orange cited its need for a global network as it expanded its reach beyond the UK following its acquisition by France Telecom.
Orange has 12.7 million UK subscribers.
Along with other major networks, its current challenge is to persuade existing customers to use WAP, texting and other functions.