The lobbying industry grew by a tepid 1.7 percent last year, according to a report released today by the nonpartisan Center for Responsive Politics. But it’s still no small number: Companies, associations and other clients spent $2.45 billion on federal lobbying in 2006, up from $2.41 billion in 2005.

And the U.S. Chamber of Commerce, along with its Institute for Legal Reform, increased its spending by 83 percent between 2005 and 2006 to $72,740,000, the CRP said.

“A year in which the Congress, by its own admission, didn’t do much legislatively and lobbying scandals made the industry cautious, it’s amazing the chamber still increased its lobbying so significantly,” said Massie Ritsch, the CRP’s communications director.

AARP came in second, spending $23,160,000, according to the CRP’s analysis of public lobbying records, while the American Medical Association’s $19,880,000 put it at No. 3.

Other big spenders for 2006 included the National Association of Realtors, defense contractor Northrop Grumman, Exxon Mobil, Verizon Communications and pharmaceutical companies Pfizer and Amgen.

— Kate Ackley