Paddy Lowe, executive director (technical) at the team, will assume Bell’s duties as part of a streamlining of the technical organisation.
According to Mercedes, Bell resigned his position in December 2013 “with the intention of pursuing new challenges outside the company”. He will therefore leave the team at the end of November 2014.
Mercedes have dominated the opening three races of the year, with Nico Rosberg triumphing in Australia and Lewis Hamilton leading the German home in successive one-two finishes in Malaysia and Bahrain.
The team reshuffled its management ahead of the 2014 season, with Ross Brawn stepping down as team principal and handing over leadership duties to Lowe and Toto Wolff, now Mercedes team executive director.