WASHINGTON -- Ross Perot sued the bipartisan commission that voted to keep him out of the presidential debates, arguing yesterday that excluding him would deepen public cynicism and cause his campaign "incalculable damage."



Shifting strategy, Mr. Perot also was negotiating to buy network TV time to air three 30-second commercials denouncing the Commission on Presidential Debates. "Where's Ross?" asks an announcer in one. In another, the announcer asks, "What are they afraid of?"



Mr. Perot complained he has been denied desirable broadcast times, and his spokeswoman, Sharon Holman, said a complaint would be filed today with the Federal Communications Commission seeking "reasonable access to network facilities and equal time."



Both the private debate commission and the Federal Election Commission were named as defendants in Mr. Perot's suit, which insists that he be included in the debates or the forums canceled. The debate commission has prevailed twice before, when sued by third-party candidates in 1988 and 1992.



Mr. Perot's suit, filed in U.S. District Court, faults the debate commission's finding that he and running mate Pat Choate have no realistic chance of being elected.



"Declaring the election essentially over for all candidates but two before a single debate takes place will only deepen the nation's cynicism about government," it states.



The suit contends that the commission, in recommending debates limited to President Clinton and GOP candidate Bob Dole, violated federal election law and certain constitutional rights of Mr. Perot and Mr. Choate.



Presidential debates are scheduled for Oct. 6 in Hartford, Conn., and Oct. 16 in San Diego. A vice presidential face-off is set for Oct. 9 in St. Petersburg, Fla.



"We are going to fight this all the way to the end," said one of Mr. Perot's lawyers, Jamin Raskin, a professor of constitutional law at American University.



The lawsuit contends that the commission violated Federal Election Commission rules requiring "objective criteria" for determining whom to include in debates. It faults the FEC for failing to enforce its rules.



Mr. Perot's lawsuit argues the debate commission used a mostly subjective standard in inviting only those it deemed to have a "realistic chance" of winning.



"The Democratic and Republican parties should not be permitted to consolidate their monopoly on the political process by closing off the presidential debates," the suit states.



Furthermore, it says, Mr. Perot and Mr. Choate have been illegally barred from the debates, "thereby causing incalculable damage to their campaigns."



The debate commission had little comment. "We're going to wait and see what the court does. Our attorneys will study whatever is filed," said commission spokesman Bob Neuman.



President Clinton had urged that Mr. Perot be included in the debates and Mr. Dole had pushed for his exclusion.



Mr. Dole, asked about Mr. Perot's lawsuit during a campaign appearance in Virginia, said only "He has a right to file. The commission voted. I didn't vote."