ZenithOptimedia will handle strategic planning for Wella, while buying will be split between Starcom Media-Vest Group and MediaCom.
Starcom handles TV, radio and outdoor buying for P&G, while MediaCom is responsible for press.
The business has moved following P&G's £2.2 billion acquisition of Wella a year ago. P&G will now market Wella brands including Shockwaves, Silvikrin and Nicky Clarke.
Wella's £45 million global creative account moved to the P&G agency Leo Burnett last November. The haircare manufacturer had previously used Bates as its creative agency in a number of markets, including the UK.
PHD said it expected the account would move eventually following the acquisition by P&G. It said that it was proud of the work it had done for Wella, including the Shockwaves sponsorship of Baywatch and partnering with Gareth Gates. Wella was also a sponsor of Comic Relief's "Red Nose Day" last year.
Wella's UK media planning and buying will now be overseen by Bernard Balderston, P&G's associate director for media. Wella's marketing department has merged with P&G's.
Last March, P&G bought 77.6 per cent of Wella's shares in a cash deal.
It hoped to boost its range of haircare brands that already included Pantene, Herbal Essences and Clairol.
P&G's strategy was to match its strength in retail haircare with Wella's strength in professional haircare. Wella estimated that it had 22 per cent of sales across the global professional salon market, putting it into the number-two position globally.