WASHINGTON – Treasury Secretary John Snow resigned yesterday and President Bush nominated Goldman Sachs’s chief executive officer, Henry Paulson Jr., as his replacement – another chapter in the shake-up to revive Bush’s troubled presidency.

“He has a lifetime of business experience. He has intimate knowledge of financial markets and an ability to explain economic issues in clear terms,” Mr. Bush said of Mr. Paulson in a Rose Garden announcement.

[Mayor Bloomberg called Mr. Paulson a “friend” and said he will be a “brilliant” secretary of the treasury. The mayor said Mr. Paulson phoned yesterday morning to say he was taking the job.

“I don’t think there is anybody more qualified to be secretary of the treasury than Hank Paulson,” Mr. Bloomberg said. “He is always the kind of person who I’ve held up as a great corporate citizen. He kept the headquarters of his company in New York City at a time when we really needed them.”]

White House officials believed that a Wall Street executive with Mr. Paulson’s talents could better make the case for the administration’s economic program.

Mr. Paulson, who also is chairman of Goldman Sachs, called the American economy “truly a marvel, but we cannot take it for granted. We must take steps to maintain our competitive edge in the world.”

A former head of railroad giant CSX Corporation who has a Ph.D. in economics, Mr. Snow has been Treasury secretary since February 2003. His departure has been rumored for more than a year.

Just last week, Mr. Bush was asked if Mr. Snow had given him any indication he intended to leave his job. “No, he has not talked to me about resignation. I think he’s doing a fine job,” the president said during a Thursday evening news conference.

But the White House press secretary, Tony Snow, said that Mr. Bush already had offered Mr. Paulson the job five days before that, during a meeting between the two. Mr. Paulson’s acceptance the next day, on May 21, was subject to a background check, Mr. Bush’s spokesman said.

Mr. Bush praised the outgoing Treasury secretary yesterday for showing “strong leadership.”

Mr. Paulson has been both chairman and CEO of Goldman Sachs since May 1999. Speculation that Mr. Paulson would take over from Mr. Snow increased after a former Goldman Sachs executive who had worked with Mr. Paulson and was leading the effort to find a replacement, Joshua Bolten, became the new White House chief of staff.

Mr. Paulson is a major Republican donor and fund-raiser.

He collected at least $100,000 for Mr. Bush’s 2004 campaign, earning the nick name “pioneer” reserved for Mr. Bush’s six-figure fund-raisers. Mr. Paulson has donated at least $68,000 to GOP campaigns and party committees so far in the 2005-06 election cycle, including $25,000 to the National Republican Senatorial Committee and $15,000 to its House counterpart, figures compiled by the Political Money Line campaign finance tracking service show.

The Senate Finance Committee is expected to act swiftly on the nomination.

Mr. Paulson is a millionaire many times over. Last year, the Goldman Sachs group said it paid Mr. Paulson $30 million in total compensation in 2004.

Mr. Paulson was known on Wall Street for his dedicated support of environmental causes. Earlier this year, he made a gift of $100 million in Goldman stock to a foundation dedicated to conservation and environmental education.