West Ham's billionaire owner Bjorgolfur Gudmundsson will take a more hands-on role after Eggert Magnusson's decision to step down as executive chairman.
Eggert Magnusson is stepping down as executive chairman
The shake-up is the next stage of West Ham's plan to break into the Premier League's top four, and includes moving the club to a new stadium.
Gudmundsson said: "It is vital we strengthen the senior team and build a management structure for the future."
Magnusson will stay on as non-executive chairman and keep his West Ham stake.
He said: "We have worked hard to create stability and optimism, but I feel the moment is right to stand back a little as we move into a new and exciting period."