The CCS is holding the pitch on behalf of a consortium of London councils.
It is looking for a shop to help raise awareness of the rise of HIV in London among African communities and "MSM" (men who have sex with men).
The campaign will also aim to increase the number of people who get tested.
The winning agency will work alongside a channel planning agency, which will be appointed separately, and the Government’s media buying shop, Carat.
In April, the United Nations kicked off a search for an agency for its HIV and Aids programme, UNAIDS. It wants a global campaign to make HIV testing "cool".