Sixty religious denominations and communities have called upon President Obama to appoint a chair for the Federal Reserve who will favor stricter regulation of the banking and nonbanking sectors. The groups favor a re-establishment of the separation between the investment and commercial banking sectors. This shift in policy, the organizations argue, will offer greater protection for the poor and middle class in the United States and around the world. Signers of the letter include Network, the Leadership Conference of Women Religious, the Conference of Major Superiors of Men and Jubilee USA Network. “Deregulation had negative effects on those living in poverty everywhere, including in countries with G.D.P.’s smaller than some Wall Street banks,” said Aldo Caliari, an economist at the Jesuit-sponsored Center of Concern in Washington, D.C.