The account was picked up by the network after a battle against MediaCom, Starcom MediaVest Group and MPG
MediaCom was thought by many observers to be the favourite to win the account because it holds the majority of the global Volkswagen media account and VW is set to merge with Porsche.
However, sources close to the situation had indicated that Porsche was "fiercely independent" about its brand, and that this was reflected in its choice of media agency.
PHD, which previously handled Porsche's media planning and buying account in Germany, will now also oversee Porsche's media in key markets such as the US, UK, China, Australia, Italy, France and Canada.
The business was previously handled by a range of agencies on a local basis. The UK account, which was previously with Starcom MediaVest Group, is likely to move into PHD Group agency Rocket.