The split with JCPR comes just months before the delayed launch of Sony's PlayStation 3 next spring.
SCE UK head of PR David Wilson said JCPR parent agency Edelman's work for Microsoft's Xbox created an ‘increasing likelihood' of a conflict of interest, so the parties had agreed to an ‘amicable split'.
Neither party would comment on fees but PRWeek understands the brief is worth at least £150,000 a year, topping £250,000 during the year of a major product launch.
JCPR will work a three-month notice period, giving the new agency a chance to bed in before PS3's launch.
Wilson plans to hold a pitch and has yet to shortlist agencies. Edelman retains Microsoft's corporate, PA and public sector account in the UK, but since August has handled Xbox in Europe.
The defection of Rana Reeves, who led JCPR's PlayStation account, to Shine Communications (PRWeek, 9 June) was not a factor in the split, said Wilson.
Consumer electronics retailers were forced to revise December sales targets last month when Sony announced the PS3 would not be available for Christmas.
Rival Nintendo is on course to launch its Wii console in December.