The city has doubled its direct subsidy for the Atlantic Yards project, adding an extra $105 million to the proposed development.

The added subsidy, which brings the city’s direct contribution to $205 million, was disclosed in Mayor Bloomberg’s preliminary budget last week.

“The additional funding is for infrastructure improvements, several of which would have been required with or without the construction of the Atlantic Yards Development,” a spokesman for the mayor’s office, John Gallagher, told The New York Sun via e-mail.

In 2005, the city and the Empire State Development Corporation agreed to a memorandum of understanding with the developer of the Brooklyn project, Forest City Ratner Companies, in which both governmental parties committed $100 million. A provision in the agreement allowed for further subsidy “for extraordinary infrastructure costs relating to the mixed use development.”

A spokeswoman for the state agency said it has no plans to change its $100 million commitment.

A spokesman for Develop Don’t Destroy Brooklyn, which opposes the project, Daniel Goldstein, said the city’s move was unwelcome, though not unexpected. “As long as they can convince the public it’s only $100 million, they’ll do that,” he said.

Forest City Ratner did not return several calls seeking comment.

Council Member Letitia James, whose district includes Atlantic Yards, was upset by the budgeting for additional funds, her chief of staff, Kate Suisman, said. Ms. James has been an outspoken opponent of the project, but Ms. Suisman said she did not think the added $105 million would derail the passage of the mayor’s proposed budget.

A former president of the Boerum Hill Association, Jo Anne Simon, said she opposes many aspects of the project, though infrastructure could be a good thing. “This is part of the problem,” she said. “Of course there are needs for infrastructure, but I don’t know why this amount of money and what it’s going to go for.”