The developer of the $4.2 billion Atlantic Yards project is coming under pressure to downsize, The New York Sun has learned.

State officials have discussed with the developer, Forest City Ratner, a reduction in the size of the project, a source said. The officials have said the downsizing should come in the next few weeks, before September 22, the end of the public comment period regarding the draft environmental impact statement, the source said. As proposed, Atlantic Yards would be the largest development project in Brooklyn’s history and create the densest census tract in America.

Forest City Ratner is seeking to build a basketball arena and 16 towers containing 6,860 apartments on 22 acres in Prospect Heights, Brooklyn, but the project has come under fire from some members of the community who say the project is too dense, will destroy the low-rise neighborhood, and further ensnarl the borough in traffic.

Many supporters of Atlantic Yards hail the project’s affordable housing component. The developer has promised that half of the project’s rental units, about 2,250 apartments, will be made available to low- and middle-income families.

The support of the Pataki administration and its leading development agency, the Empire State Development Corporation, is critical to the project’s success.The proposal is being shepherded through the approval process by the ESDC, whose board must approve the plans before they head for final approval from the Public Authorities Control Board.

City officials said yesterday that the Department of City Planning is drafting written testimony that it will submit to the ESDC that will include comments about the proposed height and how the project fits in the context of the low-rise neighborhood.

Previously, the Bloomberg administration has supported the plan without reservation based on its job creation and affordable housing components. City Hall does not have an official vote on the matter, because the proposal circumvents the city’s uniform land use review process.

Last Wednesday, hundreds of supporters and opponents clashed verbally during and outside a public hearing over the developer’s draft environmental impact statement. At the hearing, the president of Brooklyn, Marty Markowitz, tweaked his previously robust support for the project to include some new demands. He asked the state and developer to reduce the project’s scale, build a school, add a police substation, improve potential traffic problems and parking, and make sure that the project’s open space is public and accessible.

A spokesman for Forest City Ratner told the New York Post last week that it would consider the suggestions by Mr. Markowitz. The developer would not comment yesterday.

If the developer reduces the project’s size, it should not expect instant community approval of the new plan. A spokesman for Develop Don’t Destroy Brooklyn, an umbrella organization of opposition groups, Daniel Goldstein, said a size reduction would not halt a legal challenge over the proposed use of eminent domain.

Mr. Goldstein said the organization would oppose the project until the developer changes the 22-acre project footprint, considers not building the basketball arena, and takes eminent domain off the table. He said he expected a size reduction as part of the developer’s strategy to seek approval.

“They shoot for the sun so they can get the moon. When they get the moon, they act like they have listened to the criticism and responded,” Mr. Goldstein said.

Mr. Goldstein said the latest proposal is about 700,000 square feet bigger than the 8 million square feet that was originally proposed in December 2003. Opponents contend that the developer increased the total square footage to about 9.1 million square feet last September, and then in March scaled back plans by about 5%, or 475,000 square feet, to its current total size of about 8.7 million square feet.

The developer has said that the size of the project, and its thousands of market rate housing units, is necessary to subsidize the affordable units. Forest City Ratner has not said how much it stands to profit from the project.

If the developer downsizes, as expected, any decrease in the number of affordable housing units could threaten a main source of support, which includes the housing activist Bertha Lewis. A well-timed size reduction could, however, placate some politicians whose support has been conditional on changes to the current plan.

A spokesman for City Council Member David Yassky, Evan Thies, said a decrease in size would be a significant development. Mr. Yassky supports the project, but has called for a size reduction and traffic improvements.

“Finally, someone seem to be listening on the other side,” Mr. Thies said. “This is a real opportunity for the developer and the ESDC to prove to the community that they are listening to their concerns.”

Several elected officials have asked that the size and density of the project be reduced. In May, a bill introduced by Assemblyman James Brennan, a Democrat of Brooklyn, would have forced the developer to reduce the amount of square footage by about one-third. The state, in return for a reduction, would give more money to subsidize the project’s affordable housing units and for land acquisition costs. Five members of the Assembly from Brooklyn supported the bill.

Yesterday, the Empire State Development Corporation scheduled an additional public community forum for September 18. A forum is also scheduled for September 12.

If minor changes are made to the current plan, the developer would not necessarily have to submit a new supplemental environmental impact statement and the state could give its final approval soon after the public comment period concludes.