Washington ? President Bush picked Carlos Gutierrez, the chief executive officer of cereal giant Kellogg Co., as commerce secretary Monday, working to build a new economic team to help sell second-term overhauls of Social Security and the tax code.

The nomination was Bush’s first step in replacing his economic advisers. The White House offered no promise of job security to Treasury Secretary John Snow, who has made clear he wants to remain.

Officials said the challenges of the second term could require leaders with different skills from the first term when the biggest problems were pushing tax cuts and dealing with recession.

Bush called Gutierrez a visionary and one of America’s most respected business leaders, a man who rose to the top at Kellogg’s from a first job as a truck driver in Mexico City peddling Frosted Flakes to local stores. Born in Cuba and brought to America at age 6, he learned English from a bellhop at a Miami hotel.

“He is a great American success story,” the president said. “He understands the world of business from the first rung on the ladder to the very top.”

At Commerce, Gutierrez would be charged with improving the fortunes of America’s struggling manufacturing sector, which has seen the loss of 2.7 million jobs over the past four years as the country’s trade deficit has soared to record levels. He also would be a key player in the administration’s campaign for major changes in Social Security and the tax system.

The 51-year-old Gutierrez has been credited with overhauling Kellogg’s operations and providing new life for such brands as Special K. Since he became chief executive officer in 1999, Kellogg’s sales have climbed 43 percent, helping boost earnings per share by 131 percent.

The nomination added to Bush’s diversification of his Cabinet with Hispanics, women and blacks. While Gutierrez is not a Bush loyalist like other nominees, he emphasized that he shares the president’s philosophy.

“I believe passionately in your leadership and the direction you’ve set,” Gutierrez said, standing next to Bush at an announcement ceremony at the White House. “I believe in your call for a vibrant, growing entrepreneurial society, where everyone has the opportunity to experience the joy and the pride of ownership, where everyone can contribute and where everyone can benefit.”

By taking the Commerce job, Gutierrez would succeed Don Evans, one of Bush’s oldest friends, who wants to return home to Texas. Stephen Friedman, Bush’s chief economic adviser, submitted his resignation letter Monday, saying he intended to return to the private sector by the end of the year.

Snow, 65, a former chief at railroad giant CSX, took over at Treasury in February 2003, replacing Paul O’Neill, who was fired by Bush as part of a shake-up of economic advisers. While Snow has been a loyal foot soldier for Bush’s program, particularly in political battleground states, he has not been seen as a policy innovator and has not made much of an impression on Wall Street.

Unlike predecessor Evans, Gutierrez doesn’t appear to be a major Republican fund-raiser or donor. He isn’t one of Bush’s $100,000-and-up fund-raising “pioneers” and “rangers,” and he isn’t listed as a donor to either of Bush’s presidential campaigns.

Gutierrez made $10,500 in campaign donations at the federal level in the 2003-04 election cycle: $4,000 to the U.S.-Cuba Democracy PAC and $6,500 to Republican congressional candidates, data compiled by the nonpartisan Center for Responsive Politics showed.