BBDO, which New Balance added to its roster last year, will still handle the brand's athletic performance range.
In light of Mother's appointment, New Balance has also hired Savania Davies-Keiller and Roberto Crivello as in-house creative directors.
The pair will be responsible for setting the overall creative direction for the trainer brand's lifestyle category.
New Balance has heavily increased ad spending this year, with $20 million paid out during the first half of 2008, compared with $15 million for the whole of 2007.