Bell has previously worked for McLaren, Benetton and Jordan
Renault have split with managing director Bob Bell, with team principal Eric Boullier taking over the role.
Bell was promoted from technical director in the wake of the sacking of former team boss Flavio Briatore over last year's race-fixing scandal.
A spokesman said Bell's departure was "a mutual decision based on the direction the company is taking".
Renault F1 are owned by private equity group Genii Capital. The car company retains a minority shareholding.
Bell was appointed acting team principal after Briatore was found guilty of asking Renault driver Nelson Piquet Jr to crash deliberately during the 2008 Singapore Grand Prix to help team-mate Fernando Alonso's chances of winning the race.
Bell became managing director after Boullier's appointment as team principal in January, with James Allison taking over as technical director.
Renault F1 chairman Gerard Lopez, boss of Genii Capital, said: "We would like to thank Bob Bell for his contribution to the performance of the team and for helping see us through a period of transition since Genii Capital became a shareholder in the Renault F1 Team.
"We are entrusting the post of managing director to Eric Boullier and we have every confidence that, under his leadership, we will achieve our racing objectives.
"Throughout the 2010 season, we have been assessing what is required to continue improving our level of competitiveness and we believe we are well positioned for the challenges ahead."
Bell, a highly regarded aerodynamic engineer, has previously worked for McLaren, Benetton and Jordan, and joined Renault to work under former technical director Mike Gascoyne in 2001.
Bell took over the role of technical director when Gascoyne, who is now at Lotus, left to join Toyota in 2003.