Resolute has been brought on board to handle the comms activity for GSK's Kivexa drug across Europe.
This appointment comes as a global six-day conference on HIV/Aids opened in Mexico City earlier this week.
The conference was preceded by an awareness march and photo exhibition. About 20,000 scientists, government officials and campaigners are in Mexico City for the event.
As part of the brief Resolute will work with key opinion leaders in Europe and European clinicians.
The activity will concentrate on a satellite symposium taking place in November in Glasgow that is focused on personalising HIV medication for individual patients.
HIV continues to be a worldwide problem. Although globally the number of new HIV infections has declined from three million in 2001 to 2.7 million in 2007, there are now an estimated 33 million people living with HIV globally.
Last month, a United Nations programme report warned that while there have been significant gains in preventing HIV infections in a number of heavily affected countries, an Aids epidemic is not close to being over in any part of the world.
Another study found that life expectancy for people with HIV has increased by an average of 13 years since the late 1990s, thanks to better HIV treatment.
The Human Immunodeficiency Virus attacks the body's immune system, which provides a natural defence against disease and infection.