WASHINGTON – President Bush on Monday nominated John Roberts to succeed William H. Rehnquist as chief justice, and called on the Senate to confirm him before the Supreme Court opens its fall term on Oct. 3.

The swift move would promote to the Supreme Court’s top job a man who currently is being considered as one of eight associate justices.

“I am honored and humbled by the confidence the president has shown in me,” Roberts said, standing alongside Bush in the Oval Office. “I am very much aware that if I am confirmed I would succeed a man I deeply respect and admire, a man who has been very kind to me for 25 years.”

“He’s a man of integrity and fairness and throughout his life he’s inspired the respect and loyalty of others,” Bush said. “John Roberts built a record of excellence and achievement and reputation for goodwill and decency toward others. in his extraordinary career.”

The selection of Roberts, who has drawn little criticism, helps Bush avoid new political problems when he already is under fire for the government’s sluggish response to Hurricane Katrina and the president’s approval ratings are sagging.

Getting a new chief justice of Bush’s choosing in place quickly also avoids the scenario of having liberal Justice John Paul Stevens making the decisions about whom to assign cases to and making other decisions that could influence court deliberations. As the court’s senior justice, Stevens would take over Rehnquist’s administrative duties until a new chief is confirmed.

“The passing of Chief Justice William Rehnquist leaves the center chair empty, just four weeks left before the Supreme Court reconvenes,” Bush said. “It’s in the interest of the court and the country to have a chief justice on the bench on the first full day of the fall term.”

Bush said Roberts has been closely scrutinized since he was nominated as an associate justice and that Americans “like what they see. He is a gentleman. He is a man of integrity and fairness.” He said Roberts has unusual experience, having argued 39 cases as a lawyer before the Supreme Court. Bush also said Roberts was a natural leader.

The move was engineered to have all nine seats on the high court filled when the court opens its fall term.

Bush already had nominated Roberts to fill the seat of retiring Supreme Court Justice Sandra Day O’Connor. It requires just take a little paper shuffling to change the nomination for Rehnquist’s seat. Bush still must fill O’Connor’s seat but she has promised to stay on the court until a successor is named.