WASHINGTON - The FBI and Justice Department plan to expand their role in global counterterrorism operations significantly, part of a U.S. policy shift that will replace a CIA-dominated system of clandestine detentions and interrogations with one built around transparent investigations and prosecutions.

Under the "global justice" initiative, FBI agents will have a central role in overseas counterterrorism cases. They will expand questioning of suspects and evidence-gathering to try to ensure that criminal prosecutions are an option, officials familiar with the effort said.

Although the initiative is a work in progress, some senior counterterrorism officials and administration policy-makers envision it as key to the national security strategy President Obama laid out last week, one that presumes most terror suspects have the right to contest the charges against them in a "legitimate" setting.

The approach reverses a mainstay of the Bush administration's war on terrorism, in which global counterterrorism was treated primarily as an intelligence and military problem, not a law-enforcement one. That policy led to the establishment of the prison at Guantanamo Bay, Cuba; harsh interrogations; and detentions without trials.

The "global justice" initiative starts out with the premise that virtually all suspects will end up in a U.S. or foreign court of law.

"Regardless of where any bad guy is caught, we want the bureau to be in a position to put charges on them," said one senior U.S. counterterrorism official, adding that the Bush administration's emphasis on CIA and military operations often marginalized the FBI.

Like others interviewed, the official spoke on the condition of anonymity because no one has been authorized to discuss the initiative publicly.

Upon taking office, Obama shut down the CIA's secret "black site" prisons and forbade coercive interrogation techniques. That opened the door for an increased role for the FBI, which for the last year has deployed more agents and analysts overseas to work with the CIA, U.S. military, and foreign governments.

The initiative would mean even broader incorporation of the FBI and Justice Department into global counterterrorism operations. Many national security officials said it was a vindication of the FBI, which before Sept. 11 had played a leading role in international terrorism investigations.

FBI agents for years used noncoercive interrogations to thwart attacks, win convictions of al-Qaeda operatives, and gain an encyclopedic knowledge of how the terrorist network operates. But they withdrew from questioning key suspects because they opposed CIA and military tactics, often used by inexperienced contractors.

The harsh interrogations provided such bad information that U.S. agents spent years chasing false leads around the world, former FBI agent Ali Soufan told Congress two weeks ago. "It was one of the worst and most harmful decisions made in our efforts against al-Qaeda," he said.

Bush administration officials defended their tactics. "With many thousands of lives potentially in the balance, we did not think it made good sense to let the terrorists answer questions in their own good time," former Vice President Dick Cheney said in a speech this month.

Before Sept. 11, the FBI model of "informed" interrogation - knowing everything about a suspect to get them talking - was the preferred method of intelligence and military interrogators. Even veteran CIA agents said that abandoning that approach after Sept. 11 was counterproductive.

Richard Clarke, a senior counterterrorism official in the Clinton and George W. Bush administrations, said the Obama program was long overdue. "We have to return to the practice that we had before of arresting terrorists and putting them on trial," said Clarke, who added that the country's ability to do that "has atrophied."