Mining group Rio Tinto has appointed Jan du Plessis, the chairman of British American Tobacco Plc , to also head its board, the firm said on Tuesday.

Du Plessis will continue to be chairman of BAT, a post he has held since 2004, Rio said in a statement. Last month, chairman-elect Jim Leng quit Rio's board after objecting to a planned $19.5 billion deal under which Chinese state-owned Chinalco will buy stakes in Rio mines and double its stake in the firm to 18 percent.

Our immediate focus must be on giving Rio Tinto the best possible platform to create shareholder value and to weather the tough and uncertain global economic conditions, Du Plessis said in the statement.

Pursuing the completion of the transaction with Chinalco will give Rio Tinto this platform, from which we will be even better placed to prosper when we see economic recovery.

Du Plessis also serves as a non-executive director of Lloyds Banking Group Plc and is chairman of its audit committee, but he plans to stand down from that role, Rio said.

(Reporting by Eric Onstad; Editing by Jon Loades-Carter)