The competing shops have been asked to produce ideas for a digital TV and print campaign to increase audiences and attract high-profile advertisers to the channel.
Richard Gale, Playboy TV's head of marketing, said: "We're trying to legitimise adult entertainment. We've found we're appealing too much to the 'mac brigade', which isn't our most profitable market, and not enough to the kind of people who read Campaign."
The agency appointment is the precursor of Playboy TV's return to television advertising for the first time since its £1.5 million launch through Saatchi & Saatchi in October 1995. Equinox Communications will continue to handle media buying.
It also coincides with the channel's launch of five websites as part of a digital strategy to attract mainstream advertisers wanting to target a predominately male audience with substantial disposable income.
Playboy TV, a subsidiary of Playboy Enterprises run by Hefner's daughter, Christie, has about 175,000 unique site users. It argues that the figure already makes it a credible online proposition for major carmakers and an alternative platform for advertisers as the lads mag readership shows signs of decline.