Elected officials are piling on Consolidated Edison a day after the utility filed paperwork saying it may sue the city for $25 million in connection with the July steam pipe explosion near Grand Central Terminal.

Mayor Bloomberg, who has been one of Con Ed’s biggest defenders, said yesterday the city does not believe there is “any merit” to the utility’s claim. He said he assumed the move was “procedural,” but that there is no reason to think the city contributed to the problem.

The speaker of the City Council, Christine Quinn, called the $25 million notice of claim “outrageous” and fired off a letter to the company’s CEO, Kevin Burke, saying that if company officials have information about what led to the explosion they should be sharing it with the public.

Ms. Quinn, a likely 2009 mayoral candidate, also dismissed Con Ed’s claim that the paperwork it filed, which allows the company to file a lawsuit if it chooses to, is just procedural.

“If this was so routine, just filing paperwork, they would have done it the next day,” she told reporters. “But they engaged in some level of research and investigation over this period of time to make sure that there was a threshold that they might move forward with to sue. What is that information? Why hasn’t it been given to the City Council?”

A longtime critic of Con Ed, Assemblyman Michael Gianaris, said the steam pipe explosion — which resulted in about 40 injuries and prompted one death — illustrates that the government should be looking to open the doors for more competition with Con Ed.

When asked about the company’s decision to file the notice after Mr. Bloomberg had defended its practices, he said: “There’s gratitude for you.”

He said he is particularly angered that Con Ed is conducting its own investigation. “Why are we trusting them to tell us what they did wrong?” he said. “Of course, their answer is they did nothing wrong.”

A spokesman for Con Ed, Joseph Petta, disputed the claim that the utility is conducting its own investigation, saying that an independent engineering firm, Lucius Pitkin, has been hired and that the entire process is being strictly documented and made available to the city and to the state Public Service Commission. The claim says the company will seek to hold the city liable if there was a problem with any pipes, sewers, catch basins, or other infrastructure.

According to the city comptroller’s office, at least 242 notices have been filed against the city in connection with the explosion, including a $50 million claim from the estate of a woman who died of a heart attack.

The Hyatt at Grand Central and Cipriani also filed for $225,000 and $350,000, respectively.