President Bush named former New Jersey Gov. Thomas Kean, a moderate Republican with a record of bipartisan cooperation, to replace Henry Kissinger as head of a new investigation of the Sept. 11, 2001 terror attacks.

"We're not going to leave any stone unturned," said Kean, who knew several people who died in the World Trade Center.

Kean will lead a commission of five Republicans and five Democrats authorized to spend up to 18 months looking into the attacks, delving into intelligence issues as well as other areas such as aviation security and immigration.

His appointment came three days after Kissinger, the former secretary of state, resigned amid concerns about possible conflicts of interest involving his business clients and demands by some Democratic lawmakers that he identify all those clients.

"I got the call last night, Sunday night," Kean said. "I feel like a ton of bricks fell on me. The only instructions I got from the White House is to do the best job I could and to be bipartisan."

Kean said the commission will be an opportunity for the country to draw together as it did after the attacks, and he promised to deliver a comprehensive study that will be made public. "I lost a number of good friends on 9-11. So did a lot of us in this area," Kean said during a news conference at Drew University in Madison, N.J. "At this point in time the country needs to come together."

Bush, in a statement, said that Kean is "respected for integrity, fairness and good judgment. I am confident he will work to make the commission's investigation thorough. It is important that we uncover every detail and learn every lesson of Sept. 11." Bush initially resisted forming the commission.

Kean, 67, is president of Drew University, about 30 miles from New York City. He was New Jersey's governor from 1982 to 1990.

He serves on several corporate boards, including those of the international petroleum company Amerada Hess Corp., the Pepsi Bottling Group and Aramark Corp., which manages food and support services at office buildings, sports arenas and other facilities.

Aramark ran the food court on top of 2 World Trade Center as well as concessions and tours of the observation deck. Several of its employees died in the tower. Also, Kean has long served as director of Fiduciary Trust Co., a financial company that lost 87 employees in the World Trade Center.

"Assuming he has no conflicts, I hope he can do the job that needs to be done," said Kristen Breitweiser, whose husband died in the trade center Sept. 11 while working for Fiduciary Trust and who is a leader of September 11th Advocates.

Breitweiser noted that Fiduciary Trust leased office space from the Port Authority of New York and New Jersey, which would be part of the investigation.

Two days before Kissinger's abrupt withdrawal, former Sen. George Mitchell, D-Maine, stepped down as vice chairman, saying the job would conflict with his responsibilities to his law firm. Democrats replaced Mitchell with former Rep. Lee Hamilton, D-Ind.

The five Republicans members are Kean, former Illinois Gov. Jim Thompson, Fred Fielding, a former White House lawyer, former Sen. Slade Gorton of Washington and John Lehman, former Navy secretary under President Reagan.

The Democrats are Hamilton, outgoing Sen. Max Cleland of Georgia, outgoing Rep. Timothy Roemer of Indiana, attorney Richard Ben-Veniste and Jamie Gorelick, a deputy attorney general in the Clinton administration.