McGraw Hill Financial Inc.’s Standard & Poor’s unit called the $5 billion fraud lawsuit filed against it by the federal government “retaliation” for the ratings company’s downgrade of U.S. creditworthiness.

S&P said the government brought “selective, punitive and meritless litigation” after the company exercised “free speech rights with respect to the creditworthiness of the United States of America,” according to a filing Tuesday in federal court in Santa Ana, California, responding to the government lawsuit.

“Only S&P Ratings downgraded the United States and only S&P Ratings has been sued by the United States, even though the S&P ratings challenged by the United States were no different than those of at least one other rating agency and other rating agencies have made the same assertions of ‘independence’ that are challenged in the complaint as against S&P,” John Keker, an attorney for the New York-based firm, said in the filing.

The Justice Department is seeking as much as $5 billion in civil penalties for losses to federally insured financial institutions that relied on S&P’s investment-grade ratings for mortgage-backed securities and collateralized debt obligations.

In August 2011, S&P downgraded the U.S.’s 60-year-running “AAA” credit rating to “AA+” with a negative outlook.

Adora Andy Jenkins, a Justice Department spokeswoman, responded to questions about Tuesday’s filing by citing a transcript from the Feb. 5 press conference announcing the case, where Associate Attorney General Tony West said there was “no connection” to the downgrade.

“We looked at the facts, the law, and the investigation that these great prosecutors and civil lawyers put together and made a determination that the filing of these lawsuits was appropriate, but they are not in any way connected,” West, the No. 3 official at the department, said at the time. (Bloomberg)