US Debt and equity market activity rose by 25 per cent on the same period last year to hit $1.7tr (£890bn) during the first six months of 2006.
Ashurst ally McKee Nelson took top place in the manager table for all US debt, equity and equity-related deals. It notched up 493 deals, two-thirds more than its nearest rival, according to research by Thomson Financial.
McKee Nelson has remained the leading manager adviser thanks to its strength in the US securitisation market. The firm dominates the manager table for US mortgage-backed securities with 242 trades worth $139bn(£72.86bn). Its nearest rival Thacher Proffitt & Wood acted on just 77 deals totalling $44bn (£23.06bn).
On the issuer side, Sidley scoops the top spot for all US debt, equity and equity-related deals, acting on trades worth $174bn (£91.2bn). However, it falls to third place when ranked by number of deals, with Thacher in first place and McKee Nelson coming second.
Debt capital markets is also key to Sidley's position in the tables, with a lead position in the US straight debt table.
Global equity issuance sees Cravath Swaine & Moore and Simpson Thacher& Bartlett on top in the manager and issuer league tables respectively.