International firm Kennedys has become one of the biggest existing practices to convert into an alternative business structure.
The firm, whose turnover of £128.5m for 2013/14 places it comfortably in the UK's top 30, was granted an ABS licence from the Solicitors Regulation Authority, effective from 1 November.
The licence will allow the firm more opportunities to grow and more immediately to accommodate four non-solicitor partners.
Kennedys first enabled two chartered legal executives to become partners in 2009 and the ABS licence was needed to maintain the status of non-solicitor partners.
Nick Thomas, senior partner, said the firm is not looking to attract external investment and the licence is not going to change the day-to-day running of the business.
'It will help us to operate as a modern legal services business, with greater flexibility to take advantage of future growth opportunities,' he added.
The firm increased annual turnover in 2013/14 from £117m to £128.5m - of which £98.3m was generated in the UK.
The SRA granted its first ABS licence in March 2012, but so far the bigger UK firms have been reluctant to take up this option.
To date, the SRA has approved 326 ABSs, although Kennedys receives the first new licence for almost a month.
Law Society Gazette