WASHINGTON - Sen. Barack Obama said Tuesday that if he were elected president he would have his own version of President Bush's office of faith-based initiatives that would "help set our national agenda" and inject morality into policy debates about everything from AIDS to genocide.

Obama, who has criticized Bush's initiative as politicized and underfunded, would prohibit religious discrimination in hiring or services by the groups that received federal funds from his Council for Faith-Based and Neighborhood Partnerships. He estimated that the program would cost about $500 million per year. He said he would keep Bush's 11 faith-based offices and expand participation by smaller religious groups.

A former constitutional law professor, Obama said he was committed to ensuring the constitutional principle of separation of church and state. He said federal grants would go only to secular programs run by religious groups.

The prospective Democratic nominee's remarks drew much attention, as Obama again is presenting a more centrist image to voters than he did in party primary contests.

"There are some who bristle at the notion that faith has a place in the public square," Obama said. "But the fact is leaders in both parties have recognized the value of a partnership between the White House and faith-based groups." His remarks followed a visit to a community ministry in Zanesville, Ohio.

John DiIulio, a former director of Bush's faith-based program turned critic, praised Obama's proposal as "much that was best" of what Bush set out to do.

"Especially in urban America, all the empirical evidence continues to show that local faith-based organizations can make a measurable civic difference," DiIulio said in a statement released by Obama's campaign.

Critics voiced two reservations: Some said that Obama's rule to ensure open hiring would discourage some organizations from participating; others said that any partnership between religion and government risked infringing on freedom of religion.

Barry W. Lynn, the executive director of Americans United for Separation of Church and State, said he was disappointed by Obama's stand because Bush's program had failed and should be shut down. However, Lynn praised Obama's support for church-state separation in principle and his intention not to subsidize religious proselytizing.

Jim Towey, a former director of Bush's faith office who's now the president of Saint Vincent College in Latrobe, Pa., said he was encouraged that Obama wanted to continue the initiative. But Towey said he expected that the hiring mandates would frustrate many organizations.

"You're going to sap these groups of their effectiveness when you block them from hiring people who have the same heart and vision," Towey said.

Obama's stand is consistent with a faith agenda that he has long advocated. In his 2006 memoir, "The Audacity of Hope," Obama wrote that he was drawn to join a black church in his 20s because of its tradition of social change and community ministry.

Obama wrote of the danger he sees in fellow Democrats minimizing religion: "We need to take faith seriously not simply to block the religious right, but to engage all persons of faith in the larger project of American renewal."