Sony Ericsson used Edelman until April this year when it took its UK PR in-house.
However, UK marketing manager Kerry Matheson said this week that Sony Ericsson 'has struggled to be as proactive as we would have wanted this year'.
'We have been proactive with a handful of journalists but we'd like to increase our profile and have relationships with more of them,' she added.
Matheson said Sony Ericsson was considering whether to either reshuffle 'internal resources' or hire a PR agency.
Matheson, who is leaving next month to return to her native Australia, is one of three marketing managers, who report to marketing director Peter Marsden.
Since April, Matheson has been Sony Ericsson's only full-time in-house staffer handling UK press relations.
In the past year, Sony Ericsson has used Roger Staton Associates and Slice on project work.
The former worked on product launches in June and the latter worked on the 'I Spy' campaign in July.