The beauty products will be available in stores from March next year.
The agency was awarded the account following a competitive pitch. It will be headed up by Beauty Seen PR MD Jo Fox-Tutchener.
The agency will target lifestyle and beauty titles to flag up the new range.
The collection will consist of 97 beauty products. An additional 18 products will be launched four times a year to tie in with the brand's fashion collections.
Beauty Seen PR was set up in 2007 by former Estee Lauder comms manager Fox-Tutchener (PRWeek, 31 October 2007).