When Cahill Gordon & Reindel hired a heavyweight pair of Allen & Overy partners earlier this year, lawyers across the city sat up and took notice.

The New York-headquartered firm has historically had a diminutive base in London since its launch in the city in 2000. Housing just two partners  – one corporate and one litigation – the arrival of A&O’s global head of leveraged finance Jonathan Brownson and capital markets partner Jake Keaveny in August signals a new committment to the office, according to chairman Bill Hartnett.