
The fine applies to its Playboy One service, which broadcast as an unencrypted, free-to-air channel until September.
Seven programmes broadcast between September 2007 and December 2007 were investigated by Ofcom and it concluded that "the explicitness, strength and/or sustained nature of the sexual content and language was unacceptable for broadcast on an unencrypted free-to-air channel".
In addition, Ofcom said, Playboy failed to provide adequate protection for viewers who were unaware the free-to-air version of the channel would be broadcasting such explicit material.
The broadcasts investigated included sequences depicting sexual acts and strong language in a sexual context.
Ofcom said the channel's position within the "adult" sector of the EPG "could not justify broadcasting material of this nature unencrypted".
Also, Ofcom said it was concerned about the harm and offence that "such graphic sexual material could cause to viewers, and in particular children, when shown unencrypted. Viewers could have come across this content unawares."