Middle market M&A activity slowed slightly in the third quarter of 2008 according to GF Data Resources, a proprietary database that collects detailed data on private-equity transactions valued between $10 million and $250 million.

The primary valuation metric – Total Enterprise Value as a multiple of adjusted Earnings Before Interest, Taxes, Depreciation and Amortization (TEV/EBITDA) – averaged 6.1x for the third quarter, up from 5.7x for the first half of 2008 and 5.8x in the second half of 2007.

“The uptick in valuation indicates that good businesses with secure market niches and the ability to withstand larger economic uncertainty continued to be bought and sold throughout the late summer months while less strong companies were more likely to pull back from the market,” said Greenberg of GF Data Resources.