ALBANY — New York City officials confirmed yesterday that the New York Yankees are seeking more public financing to build their new stadium.

A state assemblyman of Westchester, Richard Brodsky, whose committee investigates publicly funded projects, said that the Yankees now say that if they don’t get another $400 million in public financing the club might not be able to finish the stadium.

Janel Patterson of the New York City Economic Development Corp., which is working with the Yankees, said the project isn’t threatened. But she said the city is working to relieve an Internal Revenue Service regulation that prohibits more public debt to be incurred for the stadium. Mr. Brodsky said that IRS change also is being sought to help stadium and arena projects for the Mets and Nets.

The new $1.3 billion stadium is scheduled to open next year across from the historic Yankee Stadium, which is still being used this year.

“The Yankees have expressed an interest in receiving additional financing for their project,” Ms. Patterson said yesterday. “Currently, they are not permitted to do so on a tax-exempt basis pursuant to IRS regulation.”

She said the city IDA would be willing to allow the increased funding, but no decision has yet been made.

“The city is working with the state in Washington to seek relief from the applicable IRS regulation, as this regulation has taken away a tool that would be useful for a number of important New York economic development projects, not just Yankee Stadium,” she said.

Mr. Brodsky said the president of the city’s Economic Development Corp., Seth Pinsky, “told me that the Yankees have said they may not complete the stadium if this issue not resolved.”

Mr. Brodsky, chairman of the state Assembly’s committee governing public authorities and their borrowing, criticized the closed-door dealing for millions of dollars to benefit the Yankees in the face of public transit and other needs that aren’t being funded fully.