Mendelsohn replaces Jo Smith, who was forced out of Grey after objecting to the way new chief executive Garry Lace was handling the agency-wide review that led to the job cuts.
Mendelsohn was named the number-one new business director by 北京赛车pk10 magazine in December 2002, where she was described as a "BBH lifer" with a "down-to-earth, unflappable nature". She held the role of for four years having joined the agency in 1992 as a graduate trainee working in account management. She moved into business development in 1997.
Joining Mendelsohn at Grey will be senior planner Dylan Williams, who takes the role of planning director, filling the gap created by the resignation of Claire Rossi in November.
Gwyn Jones, managing director of BBH, said: "This is not the first, nor the last time, that agencies have looked to reinvigorate their performance by luring BBH people. It's the risk you run when for years you have put a high premium on the quality of the people you can attract and hire in the first place.
"Both Nicola and Dylan have contributed to our enjoyed success at BBH and we hope this continues for them at their new agency. Working in such a different culture will certainly provide them with the biggest challenge of their careers."
Lace is under pressure from New York to turn around the fortunes of Grey London and has already filled the position of creative director by hiring Australian Dave Alberts, formerly creative chief at MojoPartners. It had been vacant for four months.
There had been worries that Grey London was not effective at competing for new business on a local basis. However, since Lace took over, Grey has already won the 拢10m Dairy Crest brief, its first UK win for some time, as well as the 拢20m Visa International account for Central and Eastern Europe, the Middle East and Africa.
The agency made 48 people, roughly one fifth of its staff, redundant at the end of February. At the time Lace said: "I'm certain that we can now draw a line under it and get on with the process of winning business, doing great work and consequently growing as an agency."
Hugh Baillie, who heads the new business department at BBH will oversee the UK activities until it is decided who will replace Mendelsohn.
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