Sidley Austin Brown & Wood and McKee Nelson have topped the US capital markets tables for 2004, according to research published this month by Thomson Financial.
Sidley displaced last year's top performer Thacher Proffitt & Wood to come first with $255.56bn (£137.07bn) in total proceeds on 457 issues, up from 259 a year ago. It represents a jump in market share from 6.6 per cent to 11.3 per cent.
However, Thacher Proffitt came top of the asset-backed securities (ABS) subsection for issuers, with a 19.5 per cent market share.
Thacher Proffitt partner Steve Kudenholt said: "Securitisation has become such a large part of the total US securities market that being number one in ABS gets you there. The home equity and sub-prime loan sectors have been enormous."
McKee Nelson, the structured finance boutique allied to Ashurst, dominated general debt issues for managers. It maintained its top ranking with $411.15bn (£220.53bn) of proceeds and 732 issues, representing a market share of 17.2 per cent. That share was up from 14.2 per cent the previous year.
McKee Nelson also upped its market share of manager work in the ABS market from 25.3 per cent to 33.2 per cent, and came second to Thacher Proffitt on the ABS issuer side, with an increase in market share from 10.1 per cent to 14.3 per cent.
McKee Nelson structured finance partner John Arnholz said: "We continue to keep a well-balanced practice, touching all major asset classes, with a particular focus on highly complex structured transactions."