Conditions looked ripe for strong growth in US mergers and acquisitions volumes 12 months ago: the economy was growing, credit markets were open and private equity firms and companies had cash to spend. But a dealmaking boom failed to materialise, however, and few now expect 2013 to be much better.

With less than two weeks to go until year-end, US targeted M&A stands at $925bn, down 8% on 2011 and below the 10-year average of $990.8bn, according to provisional data from Dealogic.