WASHINGTON — With the air of a presidential aspirant, Mayor Bloomberg used a major financial summit here to offer harsh criticism of anti-immigration proposals, the nation’s public education system, and the widening gap between America’s rich and poor.

Straying afield of the boardroom talk that dominated yesterday’s conference, Mr. Bloomberg prompted a former Treasury secretary, Robert Rubin, to remark that the mayor’s forceful commentary “sounded like something a presidential candidate would do.” The reference to Mr. Bloomberg’s rumored White House hopes drew laughter from the red-faced mayor and a smattering of applause from the Georgetown University crowd.

The mayor later acknowledged that though he has denied his intention to run for president, he has done little to tamp down speculation that he may enter the race. A former adviser, Esther Fuchs, was quoted as saying last week that there was an “80%” chance Mr. Bloomberg would run as an independent if the two parties nominated “extreme” candidates.

The contradiction between the mayor’s repeated denials and the public hypothesizing by his aides has left open the question of how seriously he is weighing a White House bid. Offering a slightly different spin than usual, Mr. Bloomberg argued to reporters after the conference that the national attention he is getting — and the attendant presidential speculation — is good for the city. “If they speculate about the presidency and it helps, I’d be derelict in my duty if I didn’t go and continue to use every advantage that I can to promote New York’s cause,” he said. “That’s what I was hired for, and that’s what I’m going to do.”

Mr. Bloomberg appeared at a conference hosted by the current federal treasury secretary, Henry Paulson, to examine ways to maintain America’s edge in capital markets in the face of increasing competition from global financial centers overseas. Participants included the chairman of Berkshire Hathaway, Warren Buffett; two former chairmen of the Federal Reserve, Alan Greenspan and Paul Volcker; and other financial leaders.

Sitting on a panel next to Mr. Greenspan, the mayor sounded the loudest alarm about threats to the city and the nation’s economic dominance, moving beyond the conference themes of regulatory policy and litigation to address deficiencies in immigration, education, and the widening income gap in America.

“This society cannot be going forward the way we have been going forward, where the gap between the rich and poor keeps growing,” he said. “It’s not politically viable, it’s not morally right, and it’s just not going to happen.”

Mr. Bloomberg said the government needs to allow hundreds of thousands more skilled workers to immigrate every year, and he cited what he called the “abject failure of public education in this country” as setting America back in the global battle for economic supremacy.
It was those remarks that got the attention of Mr. Rubin, a former Goldman Sachs executive who served as treasury secretary to President Clinton. “I was most interested in Mike Bloomberg raising this to another level,” he said. “It sounded like something a presidential candidate would do.”

The atmosphere was friendly for Mr. Bloomberg, who thrived in the business world as the founder of a financial news and information company. His fellow panelists referred to him not as “Mayor Bloomberg” but as “Mike,” and he frequently appeared to switch hats between speaking as a municipal leader and as a businessman.

The panelists also discussed the implementation of the Sarbanes-Oxley Act of 2002, the law Congress enacted to address Enron and other corporate scandals, which has drawn criticism for the high costs of compliance it has imposed on companies.

“We are doing a lot of things that I regard as unnecessary” as a result of the added regulation, Mr. Buffett said, citing the steep cost of auditing fees and the attention diverted from issues material to the companies he owns.

Mr. Greenspan warned that too much regulation could hamper the flexibility that allowed the economy to rebound quickly from the stock market crash of 1987 and the attacks of September 11, 2001. The panelists also focused on litigation, as several said tort reform was key to improving conditions for business in America and keeping companies from heading overseas.

Yet despite the complaints about Sarbanes-Oxley, there appeared to be little support for repealing it among some top executives. The head of General Electric, Jeffrey Immelt, said he and other leaders were not out to push for a “rollback” of regulation.