Claims firm Minster Law has been acquired by insurance business BGL Group – the owners of comparethemarket.com – in a deal which marks the largest outright sale of a UK law firm to date.

The deal was made possible after Minster, which has annual fee income of £107m, received approval from the Solicitors Regulation Authority (SRA) to convert to an alternative business structure (ABS).

Minster, which employs around 800 staff in York and Wakefield, focuses on personal injury, in particular road traffic accident work. The firm also offers employment, probate, wills and conveyancing services.

Meanwhile, BGL, which is headquartered in Peterborough, has 4.6 million customers and employs more than 2,400 staff across its three offices which also include Coventry and Sunderland.

As well as comparethemarket.com, which is well known for its meerkat-based advertising campaign (pictured), the group also owns brands such as Dial Direct and Bennetts bike insurance, which helped it to achieve record profits of £88m in 2012 – a 22% year-on-year increase.

The deal comes after private equity house Duke Street last year acquired a majority stake of just over 50% in the Parabis Group, the parent company of insurance litigation law firms Plexus Law and Cogent Law, in a deal which valued Parabis at between £150m and £200m.

Minster and BLG have been working together for a number of years, with the law firm being the main provider of legal services to the group. Minster was among the first applicants for an ABS licence back in January 2012; however, the SRA said the complexity of the law firm's ownership structure, which operates a corporate model, made for a detailed and drawn-out process.

Minster chairman Adrian Christmas commented: "As one of the most complex ABS applications that the SRA has had to manage, it has been, appropriately, the subject of a thorough review. Having worked closely with the SRA, we have been impressed by the rigorous and professional approach it has taken in handling this important process.

"BGL Group and Minster Law have worked closely together for a number of years. The acquisition of Minster Law will enable our partnership to develop further and allow us to strengthen the market leading service we provide to our customers."

BGL chief executive Peter Winslow said: "The acquisition of a successful law firm is an important and positive move for BGL and one that is key to our ongoing success. We have been working very closely with Minster Law for some time and there are already clear synergies between the two companies."

Minster and BGL's tie-up continues the recent trend of partnerships between law firms and insurers in the wake of the ban on referral fees. In April, insurer Ageas launched a tie-up with Cardiff based personal injury law firm NewLaw Solicitors, while insurance giant Admiral recently sealed two ABS joint ventures with law firms Lyons Davidson and Cordner Lewis.