Updated

Former Sept. 11 commissioner Fred F. Fielding will be named as President Bush's new White House counsel to replace Harriet Miers, senior White House officials told FOX News on Monday.

No confirmation is needed from the Senate as this is a presidential appointment. Miers is slated to leave Jan. 31 so Fielding, who was promised a role that would be not just counsel but congressional strategist and negotiator, would start next month.

Miers stepped down on Thursday after six years at the White House and a failed nomination to be a Supreme Court justice. A well-placed source told FOX News last week that Bush adviser Karl Rove wanted for some time to establish an independent unit in the White House to deal exclusively with the far-reaching investigations the Democrat-controlled committees in the House and Senate are expected to launch this year. Miers resignation was linked to that wish.

Since her entire career has been spent in civil litigation, Miers was considered not versed enough in criminal law and separation-of-powers issues to lead the counsel's office during a period expected to be dominated by Democrat-led investigations, the source explained. The next counsel was expected to have a strong background in criminal law, federal prosecutions and the like.

According to Time magazine, which first broke the story, Fielding was the candidate chosen by Bush Chief of Staff Josh Bolten and was considered the best choice for an expanded role for the counsel. Fielding was previously White House counsel under President Ronald Reagan and deputy White House counsel for President Richard Nixon. He also served as counsel on the Bush-Cheney presidential transition team in 2000 and 2001 and most recently was a senior partner in the Washington law firm of Wiley, Rein & Fielding.

Click here to read the Time magazine article.

"The key for the administration is going to be drawing the lines on these boundaries of executive privilege and access to documents and congressional oversight — drawing the lines around the really important issues and trying to be a little more flexible on the others," the former colleague said.

FOX News' Bret Baier and James Rosen contributed to this report.