(Sharecast News) - Aminex confirmed on Thursday that Brian Hall would step down as chairman with effect from 31 August.The London-listed company said it had now begun a selection process to appoint a new chairman, and in the interim period, Keith Phair - currently the senior non-executive director - would become interim chairman, with effect from 31 August."I would like to thank Brian on behalf of the board for his dedication and guidance over the last 27 years," said Aminex chief executive officer Jay Bhattacherjee."Since founding Aminex in 1991 he has been unrelenting in his commitment to all shareholders and has overseen the growth of the business from start-up to being a London premium listed company."We wish Brian every success for the future."