New York City’s dynamic local economy is shattering fiscal projections and will generate a geyser of tax revenues for the city and state, more revenues than expected only months ago and more for government coffers than at any point in history.

Mayor Bloomberg is expected to announce a projected surplus of $4.4 billion for the current fiscal year in his revised budget today, a record number that paints a glowing near-term outlook for the city’s balance sheet.

The record figure of tax revenue was $500 million higher than the $3.9 billion surplus projected by the mayor just three months ago, and about $2 billion more than was estimated in November. The city’s total budget is about $60 billion.

The fiscal year thus far has been a tremendous one for the city with respect to revenues, as record Wall Street bonuses, real estate prices and real estate transactions at or near all-time highs, and an overall vibrant local economy have been churning out billions in once-unexpected tax receipts.

The state, which wrapped up its budget last month, saw a surplus of $1.5 billion, a windfall that came in large part as a result of higher-than-expected incomes.

The large amount of revenues associated with capital gains have also helped boost the coffers of both the city and state, bringing in a strong flow of capital to the public sector as investors reap big gains from real estate and other investments, in part by sales spurred by a low capital gains tax rate.

Just last week, the city reported an unemployment rate of 4.3%, the lowest level since comparable measurement of the figure began in 1976. The low rate presumably drives down the use of some social services. Based on the preliminary budget released in January, expenditures on public assistance were lower than had been expected.

With such a large gap between resources and expenditures, some say the time is ripe for more structural changes in areas such as the property tax system or health care spending for city employees. “The mayor has not taken advantages of these extraordinary good times for the city to tackle long-term issues like reforming pensions for the city’s public sector work force,” a senior fellow at the Manhattan Institute, Nicole Gelinas, said.

City officials caution that while tax receipts are pouring in for now, the long-term outlook is not nearly as rosy, as estimates show a deficit as early as 2009 because of rising expenditures and a projected slowdown of the economy and housing market. The budget is forecast to be balanced in 2008; by 2011, a budget gap of $4.3 billion is projected.

The Bloomberg administration’s strategy of dealing with the surpluses has been to focus on the long term, as the mayor has chosen to roll much of the excess revenue into the next year’s budget and stow hundreds of millions away in the Retiree Health Benefits Trust Fund, rather than significantly increasing spending on existing programming.

“Mayor Bloomberg intends to use the increased revenues to prudently address the multibillion dollar budget gaps which lurk in the out-years. By taking action now, we can begin to reduce these deficits as opposed to jeopardizing our future with politically popular giveaways,” the deputy mayor for administration, Ed Skyler, said in a statement yesterday.

The mayor has also used the city’s current strong fiscal grounding to push his ambitious sustainability plan, PlaNYC, which proposes numerous initiatives that would surely require significant investment to implement.

“Our economy is humming, our fiscal house is in order, and the near-term horizon looks bright. If we don’t act now, when?” he said in speech announcing the plan on Sunday. An administration official said $199 million would be allocated to PlaNYC in the executive budget today.

The real estate market is helping to drive the surplus, as the city recognizes revenues from taxes on both record-high property values and transactions on both residential and commercial property.

While the $3.9 billion surplus that was estimated in January took account of some of the blockbuster transactions from late 2006, including the $5.4 billion sale of Stuyvesant Town/Peter Cooper Village, brokerages have been reporting strong sales thus far in 2007.

“The number of residential transactions since last fall has accelerated above what we had seen in the prior couple of years — so that would feed into the idea that you’re going to see more revenue,” the president of the appraisal firm Miller Samuel, Jonathan Miller, said.

While city revenue is at an all time high, a sociology and political science professor at CUNY’s Graduate Center, John Mollenkopf, cautioned that other indicators, such as income across all tiers, are still not at pre-2001 levels.

But because the city’s income tax system is progressive, the city is recognizing record gains from taxes. “Given that the people at the upper half to the income distribution are doing well, that helps our revenue situation,” Mr. Mollenkopf said.

The city has seen years of large surpluses under the Bloomberg administration, which has led many to claim that Mr. Bloomberg is being too conservative in his forecasts. After the release of his preliminary budget, a report from the state comptroller’s office and the City Council’s budget response each increased their revenue forecast by hundreds of millions of dollars over that from the mayor’s office.

“It seems like they’re doing the same thing again with this overly gloomy forecast of the New York City economy,” Council Member Vincent Gentile, who is on the City Council’s finance committee, said. “How many years can you go consecutively with a $2 billion surplus, a $3.5 billion surplus, and now a $4 billion surplus,” Mr. Gentile added, saying that had the estimates been less conservative, the extra money could have gone to different areas or to reducing taxes.

But the chairman of the City Council finance committee, David Weprin, said mayors frequently underestimate, and he’d rather see that than the reverse. “It’s not just Bloomberg, it’s every mayor — I think it’s institutional in that office,” he said.