Halliwells and Manchester's James Chapman & Co are to merge, but the latter firm's headline-grabbing commercial team, including senior partner Maurice Watkins, has split to join Brabners Chaffe Street.
Both mergers will take effect from 1 May following negotiations lasting just six weeks. James Chapman will add £10m to Halliwells' bottom line, swelling its revenue to more than £70m.
James Chapman's 19-strong commercial team, including Manchester United director Watkins, has join-ed Brabners in a £2m boost for the commercial practice.
Thirty James Chapman partners are joining Halliwells, but just four will join the firm's tightly-held equity. The merger follows a year of swift growth, beginning with the firm's January 2005 tie-up with Liverpool's Cuff Roberts.
Halliwells managing partner Ian Austin said the merger will will aid succession planning for its insurance team.
Brabners managing partner Michael Brabner said the commercial team was "highly compatible" with his firm.