Freshfields Bruckhaus Deringer and Allen & Overy (A&O) have bolstered their US law practices with the leading City of London firms between them hiring three partners to launch stateside antitrust practices.

Joining Freshfields are Vinson & Elkins partner and co-head of the US firm's antitrust team, Paul Yde, and Mary Jean Moltenbrey, who was in charge of civil non-merger enforcement at the US Department of Justice.

The pair are joining the UK firm's Washington office as partners and will be joined by Freshfields partner Alan Ryan, who is relocating from the firm's Brussels office to form the group.

The new antitrust practice builds on the firm's existing US law practices in arbitration, project finance, securities, structured finance, tax and a Latin America group.

The practice will focus on handling antitrust issues for Freshfields' European client base, where the firm has one of the region's most highly-regarded competition practices.

Meanwhile, A&O has hired Michael Jahne, a senior lawyer from elite New York firm Wachtell Lipton Rosen & Katz, as its first US-based antitrust partner.

In contrast with its leading London rivals, which have made no secret of their ambitions to secure a merger with a New York firm, A&O is publicly pursuing a strategy of building a US practice via lateral hires.