MTV Networks International is using Firefly to advise on corporate, consumer and B2B work in markets such as continental Europe and the UK. The agency is charged with positioning MTV as an 'authority' on digital media .
Firefly will publicise mobile content deals with major music publishers and the launch of video-over-mobile services.
MTV last week unveiled a deal with Warner Music Group to enable music fans to watch music videos on their mobiles. How they will persuade consumers to pay has yet to be decided.
The company has also soft launched MTV Load, offering free mobile content in association with Motorola.
Firefly won the newly created brief after a pitch thought to have involved Harvard PR and Bite Communications. The agency's contract is worth fees of at least £100,000.
The appointment is significant as MTV has previously focused its PR on the promotion of its traditional cable and satellite channels and programme content.
This is the first time MTV has attempted to achieve international consistency when talking about digital issues.
Firefly's brief also includes building the profile of senior MTV executives.
The broadcaster continues to use Taylor Herring for programme PR.