NEW YORK ( TheStreet) - Deal volumes for the third quarter sank to their lowest levels in three years as a lack of corporate confidence on the economic outlook continues to erode M&A appetite. There were just 2,235 deal announced in the third quarter, the worst since the same period in 2009, according to Dealogic, as uncertainty caused by the government shutdown, an end to Federal Reserve stimulus and a raft of new capital and regulatory requirements bite. For the year to September, deal volumes were down 18% on last year, to 7346, while overall deal value jumped 45%, to $861 billion, due to the return of mega-deals such as Verizon Communications Inc.'s $130 billion acquisition from Vodafone Group plc of the 45% stake of Verizon Wireless that it doesn't already own. RBC Capital Markets Corp.'s head of U.S. M&A Vito Sperduto said the government shutdown and debt ceiling debate were two major issues impacting corporate confidence. "Over the next two to three weeks, my biggest concern is the stability of the U.S. economy," he said. "Once we get past that threat, there's a solid M&A pipeline and we could see a pick up in the first half of next year." Sperduto noted that the volume in the third quarter was driven by the Verizon Wireless buyout and if the $130 billion transaction was not included it would be unlikely that overall volume in 2013 would reach the roughly $1 trillion in deal volume it did the past two years. Other dealmakers say poor confidence since the credit crisis means a sufficiently long period of stronger economic growth will be needed to prompt a sustained pick-up in M&A. "After 4-to-5 years of a challenging economy a fatigue factor has permeated the mindset of many dealmakers and any bit of uncertainty is magnified," deputy chairman of Loeb & Loeb LLP David Schaefer said. He compared this to the backdrop of optimism before the credit crisis, noting several large events -- the Bear Stearns bailout, the collapse of Lehman Brothers and massive losses by investment banks -- were needed to dent confidence and trigger a tailspin in markets. Others speak of a focus on strategic rather than opportunistic deals, with the latter more pervasive in a backdrop of greater risk appetite.