With deal volume up during the first quarter, O’Melveny & Myers, Shearman & Sterling and Covington & Burling made notable additions Monday to bolster their M&A ranks in New York.

O’Melveny, whose leadership last month vowed to ramp up its transactional offering following a disappointing financial year in 2014, announced Monday its hire of a new co-head of U.S. private equity and M&A in Tobias “Toby” Knapp, who previously served as a member of the firm-wide management committee at Jenner & Block.