Mourant is representing Grant Thornton Advisors on the expansion of its multinational platform through the pending acquisition of Grant Thornton Limited, Channel Islands.
Subject to regulatory approval and standard closing conditions, the Channel Islands business will form part of Grant Thornton’s rapidly expanding platform, formed in January 2025 with Grant Thornton Ireland and bolstered by combinations with the Grant Thornton firms in Switzerland/Liechtenstein, the UAE, Luxembourg, the Cayman Islands and the Netherlands (some acquisitions remain subject to regulatory approvals).
The expansion will create a platform of approximately 13,500 professionals across nearly 60 offices, backed by an investor group led by New Mountain – a growth-oriented investment firm with c.US$55 billion in assets under management.

A multidisciplinary team from Mourant’s Jersey and Guernsey offices has been working closely with Grant Thornton alongside members of Simpson Thacher’s New York and London offices. The team includes members of the firm’s Corporate, Finance, Employment, Property and Regulatory Advisory teams on both Islands, supported by partners in Mourant Consulting and Mourant Governance Services.
The pan-Island Mourant team is led by Mourant Law LP Corporate Partners John Rochester (Guernsey) and Neil McCarroll (Jersey), and also includes Helen Wyatt, Rachel Guthrie, Simon Gould, Carla Benest, Gary Hall, Tom Hardy, Ben Jones, Jula Le Cornu, Corrie Howarth, Paul Green, Amelia Bridel, James Frudd, Katie Phillips, Laurie Child, Georgina Cook, Julie Melia and Sally Rochester from Mourant Consulting.
John Rochester (main picture) commented: “This has been a fantastic transaction to be involved in, and it’s a pleasure to have helped facilitate Grant Thornton’s ambitious strategy to build its multinational platform.
“This significant deal really underscores the depth and breadth of our transactional and advisory expertise and is a perfect example of our ability to provide seamless multidisciplinary support on the most complex cross-border transactions. We’re delighted to have worked alongside the Simpson Thacher team, and to have engaged closely and collaboratively with Grant Thornton, to be part of this exciting development.”