However, it would not comment on whether or not the account would go out to pitch.
The account is the last of United's high-profile pieces of business to remain in question. Grey was awarded its COI Food Standards Agency and Home Office business, but the remaining accounts have gone to other agencies.
At the same time, Grey has confirmed that it will hire four United employees. Rhona Cairns, the former United deputy managing director; Jason Cobbold, the ex-client services director; and Katie Halling, the former European new-business director, all become managing partners. Nils Leonard, the former United chief designer, has been hired as the UK creative group head on its Hugo Boss account.
The agency is still in talks with Richard Huntington, United's planning director. It is thought that, if hired, he will replace John Lowery, who left Grey London in April to take on planning tasks within the agency's European network.
Chris Hirst, the Grey managing director, said: "The energy, passion and dynamism of this group will be a perfect complement to the fantastic team we have in place."