Fidelity Investments, one of the largest US mutual fund firms, has appointed a president of its holding company, FMR, following a series of executive reshuffles and a lowered credit rating.

Rodger Lawson will take on the role of president of FMR. He will be responsible for Fidelity Employer Services Company, Fidelity Investments Distribution and Operations and Fidelity Technology. He will report to Edward Johnson, Fidelity Investments chairman and chief executive.