Advertising holding company Interpublic Group (IPG), parent to McCann Erickson Worldwide; Deutsch Inc. a Lowe & Partners Company; DraftFCB and many others released its Q3 earnings report today.

“Revenue of $1.43 billion in the third quarter of 2009 was down 18.0% compared with the same period in 2008,” the company reported in an earnings statement. “For the first nine months of 2009, revenue was $4.23 billion, down 16.5% compared to the first nine months of last year.”

The report, which follows Havas and Omnicom, shows the worst results so far (though neither Havas nor Omni had good results, either). Part of the problem is undoubtedly Campbell Ewald client General Motors &#151 a company that once lead the industry in volume scaled back to a trickle over the last year.

One piece of this news you may have predicted: operating costs were down for the advertising giant. “During the third quarter of 2009, salaries and related expenses were $943.5 million, down 13.7% compared to the same period in 2008.” Even with diminished costs, the results are not pretty. Stay tuned for WPP’s earnings report tomorrow.

More: “Omnicom Earnings Report: Year Over Outlook is Down”