Beachcroft LLP and Davies Arnold Cooper LLP have merged to form DAC Beachcroft LLP.
The new firm employs more than 2,000 people across the UK, Europe, Asia Pacific and Latin America and provides a full service claims, transactional, commercial, risk and advisory capability.
It works with clients in a select range of industry sectors and specialises in health, insurance and real estate.
The number of partners in the merged firm is 230 and it is expected to generate annual turnover of around £190m.
It has UK locations in Birmingham, Bristol, Leeds, London, Manchester, Newcastle, Newport and Winchester
DAC Beachcroft's leadership will comprise a board and an executive committee led by senior partner Simon Hodson and managing partner Paul Murray respectively.
The new firm will also have practice group and sector heads leading teams of legal experts.
They include corporate and commercial practice group head Martin Cannon, who is based in Birmingham.
Mr Hodson said: "This is a significant landmark in the history of both firms as we join forces to create DAC Beachcroft. The abundant synergies between the firms are illustrated not only by the sectors in which we operate but also by the full range of services we can now offer clients.
“Covering both bespoke high-value instructions through to high volume low-cost work, we are ideally positioned to cater for the changing legal needs of our clients.
“Insurance and healthcare are both industries where the new firm will continue to lead, however an added bonus of the merger is the significant increase in our real estate capability across the UK and in Madrid."
Mr Murray added: “I am very pleased with how the integration has gone so far. This is an on-going process that will be fully completed over the next 12 months.
“Nevertheless, our management teams have been very professional in their approach and the practice group heads have all started mapping clients from both firms and setting the strategy for their respective groups.
“Overall, I am most pleased with the cultural fit of the two firms - we actually get on together very well."