The online retailer, owned by JD Williams, has appointed the property advisor to find three trial stores on high streets in the North West.
The aim is to open the Simply Be stores by September with more scheduled to open in out of town areas next year.
JD Williams has also retained GL Hearn to advise on the continuing expansion of its other existing high street brand High & Mighty, which is looking to open an additional three stores in the UK next year.
Brian Sloggett, GL Hearn managing director, said: "We are delighted that JD Williams has appointed GL Hearn as sole agent for the Simply Be and High and Mighty brands. We look forward to bringing the full weight of our retail expertise to bear support to the continued expansion of High and Mighty and bring Simply Be's successful online brand to the High Street."
JD Williams is part of the Manchester-based N Brown Group.
Within N Brown Group's results announcement in May, covering the year to 26 February 2011, it said Simply Be reached revenues of £100m with growth in both the UK and international markets.