M&A pros polled in December reported growth in deal flow but at a slower pace than in November, according to the Mid-Market M&A Conditions Index (MACI), a barometer created by Mergers & Acquisitions and sponsored by PwC. (See related graphic.)

Separately, Thomson Reuters numbers based on completed deals also indicated that December did not deliver the tax-fueled year-end boost of the past few years. 

The MACI Composite score dipped to 54.5, down from 56.8 in November. Early-stage index components Leads and Signed Letters rose, suggesting the middle market will continue to expand in 2015.

December was expected to be more fruitful. By contrast, October and December each delivered 260 deals in 2013, making them among that year’s most successful months when it comes to inking middle-market M&A.

The MACI is a diffusion index, derived from monthly surveys of approximately 250 executives. Readings above 50 indicate an expansion in M&A activity, and readings below 50 indicate a contraction.

For more on December dealmaking, see Yahoo’s Purchase of Video-Ad Service BrightRoll Ranked Among December’s Most Interesting Deals. For the November edition of MACI, see November Deal Tally Keeps 2014 M&A on Track to Beat Recent Years.