The biggest portion of the business is the £6 million advertising account held by Rainey Kelly Campbell Roalfe/Y&R, which the agency has held for more than 10 years.
This is the first full pitch the train operator has run since the company launched in 1997, following its successful bid for the InterCity franchises of the Cross Country and West Country trainlines.
The digital element of the business has been handled by glue London since 2000. Craik Jones Watson Mitchell Voelkel picked up the DM in the same year after Virgin Trains parted company with HPT Brand Response.
It unclear whether the review will include media duties, which are currently handled by Manning Gottlieb OMD.