The organisation is looking to rebrand all of the sites under one common recognisable theme. The account also covers websites for Enjoy England, the domestic tourism arm of VisitBritain.
Agencies have already received the briefing, but the pitches have yet to take place. They are expected to begin in the following two weeks.
The move is being made as VisitBritain continues to invest heavily in digital in a bid to bring more advertisers and tourists to the UK market in the face of funding cuts enforced by the Department for Culture, Media and Sport.
In November last year, the DCMS announced that it would be slashing VisitBritain's funding by 18 per cent over the next three years, cutting the organisation's ability to run big ad campaigns in the run-up to the Olympics.
It recently invested in a campaign to lure influential overseas bloggers to the UK in a bid to promote the country on the back of the upcoming James Bond film, Quantum of Solace.
The bloggers from around the globe will "live like Bond" in Britain and recount their experiences. They come from websites such as Italy's Blog.screenweek.it, Japan's Cinemacafe.net, Germany's Moviemaze.de and the Los Angeles-based Comingsoon.net and Chud.com.
In February, Enjoy England boosted its digital marketing strategy by including a series of social-media elements in its web portal.