Fidelity Investments said it has put James Catudal, who already manages three of its funds, in charge of the $6.24 billion Fidelity Growth and Income Portfolio Fund, succeeding Timothy M. Cohen.
The fund, which invests a majority of its assets in common stocks, has lost more than half its value in the last six months as equity markets have plunged.
Mr. Catudal, who joined Fidelity in 1997 as an equity research analyst, will continue to manage Fidelity's Advisor Growth and Income, VIP Growth and Income Portfolio, and Stock Selector funds.
Sophie Launay, a Fidelity spokeswoman, said Tuesday that it thought the manager switch was in "the best interest of the shareholders of the fund" and a natural extension of Mr. Catudal's duties at several other funds.
Last year the Fidelity Growth and Income Portfolio Fund dropped 51%, while the Standard & Poor's 500 dropped 37%. The fund ranked 543rd among the 545 in its sector for 10-year performance, according to Lipper Inc. It earned just one star out of five in Morningstar Inc.'s rating system, which assesses how well funds have balanced risk and return in the past.