The agency scooped the business for the online financial service provider without a pitch. The appointment was made by Nick Cross, Egg's chief marketing officer, who joined the company from
Selfridges in March.
The appointment is a blow to HHCL, which launched Egg for the Prudential in 1998. It is also currently facing the loss of its £15 million AA advertising account, which is seeing presentations from
rival agencies.
Cross will oversee Egg's launch into France and Germany in June next year. He appointed Mother in a move which Simon Burridge, the chairman of HHCL, called "a very addled decision".
"We're absolutely baffled by it all," Burridge said. "The campaign we've been doing had been incredibly successful." He added: "It's very sad that a commercial agency that is doing fantastically well on behalf of a client in terms of business performance is not enough."
Cross said: "We are at an important stage of our growth and it is an appropriate time to re-evaluate our brand position. HHCL has done a great job getting us to where we are today, and now we're moving into another phase, we need to inject fresh ideas."
Mother, which has resigned its HFC Marbles account to take the Egg business, has no international network. The agency is likely to align itself with another network to service the business. Commenting on Mother's international capabilities, Stef Calcraft, a partner at Mother, said: "There's a series of avenues open to us and we're looking at all of them currently to see which makes most sense for Egg and for Mother."
Egg has a customer base of 1.8 million. It made a name for itself by reshaping the way consumers look at financial services in an original way.
Burridge said: "The 'we love you' campaign attracted 140,000 new card holders, which enabled Egg to say to the City it was going to go into profit this sector. We're just baffled that - along with repeated assurances and confidence at how well we're doing - the account moves at the sole behest of Nick Cross."
HHCL has produced some acclaimed work for Egg. Its launch campaign featured Zoe Ball and Linford Christie, and it recently launched a campaign featuring Daisy Donovan trying to buy a Russian husband with her Egg card.
Calcraft said: "Egg is a great pioneer brand that has achieved a lot in its short life. Its over-riding ambition to accelerate the rate and scale of its development is infectious."
Egg called a media review in September out of PHD. Starcom Motive, MindShare,
MediaCom and OMD are pitching. Peter Hawtin, who ran the media pitch, has left the company, but his departure will not delay the pitch.