The firm, which has more than 4,500 vehicles across the capital, has put an RFI out through AAR as part of a closed process.
It follows US-based equity firm The Carlyle Group snapping up a majority stake in the business estimated to be worth £300m.
A spokesman for Addison Lee pointed to the US deal as a reason for the review, which sees Ogilvy repitching for a newly expanded brief after picking up the work last July.
The comms account will be extended beyond its current corporate focus, with stronger consumer and digital elements.
"Following the investment we’re seeking to expand the business so we’re looking at an bigger brief and more involvement in social media," he added.