In a joint statement issued Tuesday evening, Mayor Michael Bloomberg and Assembly Speaker Sheldon Silver expressed “disappointment” that that negotiations over development of the World Trade Center had yet to yield an agreement.

Blomberg, who had set Thursday, June 11 as the date by which the Port Authority of New York and New Jersey and Silverstein Properties would agree on a new “roadmap” for continuing construction at the World Trade Center site,  was hoping a deal would be announced as soon as Monday, June 15. The two sides have been squabbling for months over construction financing for developer Larry Silverstein’s three proposed office towers along Church Street, and the prolonged impasse now threatens a near halt of work on the site.

"While we have not yet been able to reach consensus with the Port, the cause is too important to give up," the statement read. "We will continue to work with all the parties to fulfill our collective obligation to rebuild the site.”

A spokesman for the Port Authority said the agency "will continue to negotiate in good faith."

"We are working with all parties to advance the private development in a way that protects public resources for the people of this region," Port Authority spokesman Steven Coleman said Tuesday night.

Silverstein, unable to secure loans to fund construction of three massive office towers, wants the Port Authority to back financing for his Towers 2 and 4. The Authority, which is building 1 World Trade Center and the new transportation hub, has balked at the idea, and instead offered to invest close to $1 billion in the construction of Tower 4 in exchange for a share of the building’s rent revenue.

If a deal is not reached soon, progress on the much-delayed site as a whole could again slow to a crawl. At Bloomberg’s invitation, all of the major stakeholders in the site’s reconstruction—including Silverstein,  Speaker Silver, New York and New Jersey Governors David Paterson and Jon Corzine, and the Port Authority’s chairman Anthony Coscia and executive director Christopher Ward—met on May 21 after Silver said in a speech that he was “fed up” with the stalemate between Silverstein and the Port Authority.

The morning after the June 11 deadline passed, Silver was more diplomatic in his assessment of the negotiations.

“It’s obviously complex,” Silver said. “Financing was available two, three, four years ago to complete these projects, but everything was delayed and wasn’t coordinated very well. Hopefully we can move toward a conclusion in the very near future. We don’t want lot of false starts and photo opportunities.”

A source familiar with the negotiations said the two sides have spent the last several weeks since the May “summit” arguing over whether Tower 2 ought to be built immediately or put on hold until the commercial real estate market in Lower Manhattan recovers. Earlier this week, the source said, Silverstein offered to pay for much of the below-ground infrastructure work on the eastern part of the site, work that the Port Authority is years behind in completing. In exchange, the Authority would agree to serve as a guarantor for construction loans for Towers 2 and 4, and build a six-story mall-type “podium” at the site of Tower 3. 

“We have made significant progress over the past three weeks,” Silverstein said in a statement. “I am confident that we can find a way to move forward together. As I’ve said many times before, failure is not an option.”

A spokesman for the Port Authority declined to comment on any part of the negotiations. Last month, the Authority offered to help fund Tower 2, but only if Silverstein committed $370 million of his own money—and another $430 million in insurance money he received for the destroyed World Trade Center—and agreed to surrender entirely the site for Tower 3, a source familiar with the negotiations said. Silverstein would also have to agree to stop charging the Authority the $300,000-a-day fee he collects for the late delivery of the sites for Towers 2 and 3, and give back the money he’s already received.

Another offer from the Port Authority would have the agency build the first few floors of Towers 2 and 3, allowing it to complete infrastructure work needed for the memorial museum and transit center. Those above-ground buildings would be outfitted with retail tenants while construction of the towers remained on hold until the commercial rental market recovers. Christopher Ward, the Authority’s executive director, has said that backing financing for Silverstein’s office towers before demand for office space Downtown resurges would destabilize the market.

The Port Authority seems to be alone in its opinion that the real estate market will not be strong enough to support three new office towers—Silverstein’s Towers 2 and 4 and the Authority’s 1 World Trade Center—among the reconstruction leaders participating in the negotiations. However, Govs. Paterson and Corzine—who ultimately control the Authority—have both said they are reluctant to inject public money into the private developments.

On June 8, the New York Times reported that the city has offered to contribute up to $100 million to cover any shortfalls in the financing of Tower 2. Bloomberg’s press office said it would not confirm the offer. Both Bloomberg and Silver have both said publicly that they are confident Lower Manhattan’s real estate market will turn around by the time Silverstein’s towers are completed.