It appears that Mayor Michael R. Bloomberg's attempt to usher in an era of reconciliation and compromise at ground zero is over. The developer Larry A. Silverstein, who is to build three towers at the World Trade Center site, opened up a new front Monday in his dispute with the Port Authority of New York and New Jersey, saying the authority has violated the development agreement at ground zero and is hopelessly behind schedule. Silverstein said the authority's delays and failures over the past seven years prevented him from obtaining financing for the three office towers at the trade center site 'in a much more positive economic climate' than exists today. Silverstein's latest move seems designed to pressure the authority to acquiesce to his demand that it guarantee as much as $3.2 billion in financing of two of the three office towers he is to build at the site. It also highlights the failure of Bloomberg's highly publicized effort to resolve the impasse between the two sides. After more than two months of high-level meetings among Silverstein and city, state and Port Authority officials, Bloomberg released a statement Monday afternoon acknowledging that the two sides were farther apart than ever, although he blamed it on the Port Authority's intransigence. 'Unfortunately, not everyone worked as hard as necessary to find a solution,' Bloomberg said in the statement. 'We are one step closer to stalemate today, but a solution does exist -- and we will not stop working until we get there.' Christopher O. Ward, executive director of the Port Authority, blamed Silverstein for 'walking away from the negotiating table simply because the public has been unwilling to sacrifice critical transportation projects to subsidize private speculative office space.' Bloomberg held a meeting at Gracie Mansion in May in an attempt to prevent a logjam after the authority and Silverstein stopped talking. Recriminations, rather than resolution, followed when various proposals failed to satisfy one side or another. In a letter to the Port Authority on Monday, Silverstein formally started arbitration, claiming that the authority had violated a 2006 agreement governing development at the 16-acre site. Silverstein is demanding that within the next two weeks, the authority detail how it will fix the problems at ground zero, where, he contends, the authority is years behind in completing the transit hub, a vehicle screening center for buses and trucks, and the underpinning of the subway line that bisects the site. The developer says that he has paid more than $800 million in rent and has started building his first tower, but no longer knows when or if related elements of the project will be completed. If the two sides fail to come to terms, the matter would then go to a panel of three arbitrators and Silverstein would seek damages. The authority is already paying Silverstein $300,000 a day in penalties -- more than $100 million since July 2008 -- for failing to complete the predevelopment work on two of Silverstein's three sites. Executives at the authority say they expect to finish by this fall. 'We are certain that Silverstein Properties understands that an arbitration decision under the development agreement will not resolve when there will be a market for two private office towers on the site, and how this speculative private office space should be financed,' Ward said. The authority has insisted that it would have to slash its capital budget and postpone or eliminate projects in New York and New Jersey if it were to guarantee the financing. Silverstein was to build the towers with a combination of insurance proceeds, tax-free bonds and private equity and financing. But lenders are reluctant to finance real estate projects today, and few, if any, tenants are willing to lease expensive new towers when rents are falling sharply at existing buildings. Some real estate executives, civic groups and Port Authority officials say that the towers should be built over time, while Silverstein and Bloomberg want it done now. After years of delay, Ward emphasized that work continues at the site, where the authority is building the Sept. 11 memorial, the transit hub and its own office tower. At the same time, Silverstein is erecting the first of his three towers along Church Street. But many officials fear that the momentum at the trade center site will vanish if the dispute lingers. 