BlackRock Inc., the world’s biggest asset manager, replaced portfolio managers at funds including those that invest in energy as it seeks to improve performance at actively run products.

Natural resources funds including the $773 million BlackRock Energy and Resources Portfolio and the $384 million BlackRock All-Cap Energy and Resources Portfolio will now be managed by Robin Batchelor and Poppy Allonby, according to a filing Tuesday by the New York-based company with the U.S. Securities and Exchange Commission. The funds were previously managed by Denis Walsh and Daniel Neumann, who took over after former manager Daniel Rice said in June he was stepping down to avoid the appearance of a conflict of interest.

BlackRock, which manages $3.8 trillion, is seeking to improve the performance of actively managed funds as deposits trailed those of index-based investments. BlackRock hired Chris Leavy in October 2010 from OppenheimerFunds Inc. to oversee fundamental equity, and last year reorganized its bond unit to give more autonomy and accountability to individual managers.

Rice, who helped manage five energy and natural resource mutual funds at BlackRock, stepped down last year amid an incident related to disclosure. Rice is one of the founders of Rice Energy, a company with a subsidiary that has a joint venture with one of the top holdings of a mutual fund he managed.