BlackRock announced at the weekend that Rice had stepped down as manager of the BlackRock Energy & Resources Fund.

The possible conflict stems from a joint venture formed with Alpha Natural Resources and a subsidiary of the natural gas drilling company founded by Rice.

Since that joint venture, BlackRock increased its ownership in Alpha Natural Resources.

"BlackRock is committed to avoiding not only actual conflicts of interest, but even the appearance of a conflict. As we have worked through with Dan Rice how to best avoid any perception of conflict involving his family's energy company, Dan has decided to retire from BlackRock," a spokeswoman said in an e-mailed statement.

Denis Walsh and Dan Neumann, who already serve as lead manager and co-manager of the five funds involved, have replaced him on the five funds. Rice will work with BlackRock with transitioning the institutional private funds, which should be completed by December, the spokeswoman said.

"For the period of this transition, BlackRock has put in place a number of enhanced procedures to ensure there is not even any perception of a conflict, while serving the best interests of our clients," the spokeswoman said.

(Reporting By Jessica Toonkel; Editing by Walden Siew and Marguerita Choy)

By Jessica Toonkel

Stocks treated in this article : Alpha Natural Resources, Inc., BlackRock, Inc.