FORTUNE –Are we experiencing a new normal for mergers and acquisitions?

Six months ago, we heard that low Q1 M&A activity was just a holiday hangover. Three months ago, we heard that low Q2 M&A activity was an anomaly — and that the pipeline was stuffed with transactions that hadn’t quite been able to cross the finish line. But as the third quarter now comes to a close, the downward trend shows no sign of abating.

Preliminary data from Thomson Reuters shows an 18.3% decline in global M&A activity, when comparing Q3 2012 to Q3 2011. Year-to-date volume is down a whopping 38%, including nearly 45% in the U.S.

In fact, the numbers are rough in virtually every related data set. Year-to-date European M&A is at a 10-year low, and quarter-over-quarter volume fell approximately 42%. U.S. activity is at a nine-year low, while Asia is reporting its weakest mark since 2005.

The only potential bright-spot is for private equity-backed deals, which climbed 16% in Q3 from the prior quarter. But even there the larger picture is cloudy, with year-to-date activity down 10 percent.

Yes, 2012 still has another quarter to turn things around. And deal pros insist that they are as busy as they’ve ever been, with rising public equities prices making corporations more willing to buy and sell. Hope springs eternal… Or, if not eternal, at least it springs for another three months.

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