The three largest deals for the quarter were in the healthcare and utility and energy sectors. They included Thermo Fisher Scientific Inc.'s acquisition of Life Technologies Corp. for $15.7 billion, Pfizer Inc.'s offer of a share exchange to reduce its 80.2% stake in animal health business Zoetis Inc. for around $14.7 billion, and Berkshire Hathaway Inc. acquiring NV Energy Inc. for $10.4 billion.

These were overshadowed by megadeals in the first quarter that included the $27.5 billion acquisition of H.J. Heinz Co. by Berkshire Hathaway and 3G Capital and the $20.7 billion privatization bid for Dell Inc. by Silver Lake and the company's CEO.

Boutique advisers -- such as Evercore Partners Inc., Houlihan Lokey and Moelis & Co. LLC -- were somewhat better-positioned in the current market than bulge-bracket houses given the dearth of large deals, Feinstein said.

His colleague, senior vice president Darren Novak, also noted that M&A teams at larger law firms were being squeezed by the lack of large-cap deal activity.

Deal activity for the second quarter represents a 27% drop on the first quarter, or a 35% fall on the prior corresponding period.

Written by Jane Searle in New York

If you liked this article you might like

The 6 Medications Being Used to Tackle the Opioid Epidemic

Allergan's Restasis Patent Transfer to Face Precedent-Setting Legal Battle

Friday Selloff May Be On Its Way; Tenet Gears Up for Sale -- ICYMI

Dow Posts Fresh Record, Third in a Row, but S&P 500 and Nasdaq Fall