Virgin Media currently works with PrettyGreen and extended its contract with the agency last year to include work on the Glasgow 2014 Commonwealth Games and V Festival.
Bray Leino also works with Virgin Media, which recommended the agency to its sister brand Virgin Atlantic in 2013 to promote the airline’s short-haul UK flights market.
The process is being led by head of media relations Gareth Mead, who said: "We have defined how we will work with our agencies more tightly ahead of what should be an exciting 2015."
Mead added that PrettyGreen and Bray Leino will remain working with the company.
Virgin Media is expected to make an announcement in the next three weeks.