Moving swiftly, President George W. Bush will nominate John Roberts to succeed William H. Rehnquist as chief justice of the Supreme Court, a senior administration source said Monday. The president was to make the announcement in the Oval Office before leaving for another trip to the hurricane-battered Gulf Coast, The Associated Press reported. Bush met with Roberts at the White House on Sunday evening for about a half an hour and then offered him the top position at the top U.S. court on Monday morning, the administration official said, speaking on condition of anonymity because Bush had not announced his selection. Bush already had nominated Roberts to fill the seat of retiring Supreme Court Justice Sandra Day O'Connor. It would just take a little paper shuffling to change the nomination for Rehnquist's seat. The president still wants Roberts to be on the bench when the Supreme Court resumes its work on Oct. 3, the official said. That means Bush would have to find a new nominee for O'Connor's seat. She has offered to remain on the bench until a successor is seated.