The costs of building the proposed new Yankee Stadium in the Bronx would outweigh the benefits to city residents and taxpayers, according to a report released by a government watchdog group yesterday.

The report from Good Jobs New York said the total public cost for the project, including subsidies, expenses, and lost revenue, is close to $500 million-far more than the $290 million in projected benefits. The analysis was based on figures provided by the city.

The director of Good Jobs New York, Bettina Damiani, said the city and state should slow down the project approval process and negotiate a better deal for taxpayers.

“The city can not give away the store to a company that has tremendous access to other financial opportunities,” Ms. Damiani said. “This is the poorest congressional district in the nation and the richest sports franchise in the nation.”

The organization’s findings were disputed by Yankees, city, and state officials. They questioned the report’s accuracy and defended the stadium project on the grounds that it will deliver jobs and private investment to an impoverished region of the Bronx.

The city has said it plans to spend $135 million to create new parks and enhance infrastructure, and the state has agreed to pay $70 million for construction of additional parking facilities. The Yankees will pay about $800 million for the construction costs of the proposed 51,800-seat stadium.

The president of the Yankees, Randy Levine, told The New York Sun yesterday that the report was “riddled with errors,” particularly in its calculations of what the deal would cost the city. Mr. Levine said the city would end up “in the black” compared to what it would pay in maintenance costs should the old stadium stand and continue to deteriorate.

“The only public investment here is for infrastructure, which is an appropriate use of government funding,” said Mr. Levine, who served as the deputy mayor for economic development in the Giuliani administration. “Compared to other teams’ transactions with other municipalities, it seems ridiculous for anybody to be complaining at the levels of investment that are taking place here.”

Mr. Levine added, “It’s no secret that much of the private investment is taking place in the Bronx based on the assumption that there would be a new Yankees Stadium.”

Last week, the City Council gave final approval to a $394 million shopping mall just south of the current Yankee Stadium on the site of the Bronx Terminal Market. There have been several recent reports that residential real estate in portions of the South Bronx is on the rise.

A spokeswoman for the city’s Economic Development Corporation, Janel Patterson, said in a statement, “While the old stadium cost the City over $30 million to maintain in the past five years alone, the new stadium will result in thousands of new jobs and play a major role in the revitalization of the South Bronx.”

Representatives of some community groups opposing the project were on hand yesterday at the Good Jobs New York press conference. Neighbors complain that the 22-acre stadium project would eliminate much of two popular neighborhood parks. They say the Yankees and city Parks Department plan to replace the parkland in two separate groupings, near the stadium and along the Harlem River, is inadequate.

Yesterday, the groups’ representatives said the community has been excluded from the stadium planning process.

In an advisory vote last fall, the local community board rejected the stadium plan. But it was recently approved by the president of the Bronx, Adolfo Carrion, and is now being considered by the City Planning Commission, which must weigh in on the stadium project by February 27. If approved, it will head to the City Council for final approval.

The state Legislature and the City Council have already approved the transfer of parkland to the Yankees.

Mr. Levine said yesterday that negotiations over a community benefits agreement were near completion. He said he expected the agreement would be “much more significant” than a $5 million agreement signed last week between the developer of the nearby Gateway Center mall, local elected officials, and some community representatives.

The city will hold a public hearing on March 9 over a proposed tax-exempt and taxable bond issue of up to $930 million for the Yankees to pay for the stadium construction.