DLA Piper is the most notable absentee from the first joint panel of the Co-operative Group and Co-operative Financial Services (CFS).
DLA Piper has been used to advise on property, commercial and litigation, but was embarrasingly dropped by the Co-op midway through a landmark dispute with ICL, which ultimately resulted in the overhaul of the Technology and Construction Court.
Herbert Smith advised CFS on a restructuring of its insurance business in January, which split the general and life insurance businesses of subsidiary the Co-operative Insurance Society.
CFS director of legal and regulatory services Peter Kerns and Co-operative Group head of legal services Philip Hardman selected the panel firms jointly.
Kerns said: "This joint venture is unique in that it is the first time that the Co-operative Group and CFS have come together to appoint a single panel of commercial law firms. We're all confident that this coming together will result in a cost-effective and proficient service for both businesses."
The panel, which Kerns said is for "high-end financial services and M&A activity", is separate from the seven-firm panel announced in September by Co-operative Legal Services.