Charles Russell Speechlys (CRS) has sealed a deal to merge with City sports law boutique Couchmans, following the departure of several sports-focused partners from both firms last year.

Couchmans' four partners and seven fee-earners will join CRS next Monday (22 January), bolstering the UK top 50 firm's sports practice, which saw four partners leave to found a new boutique, Northridge, last October.

Couchmans, which was founded in 2001 by chairman Nic Couchman, works with clients including  Ascot Racecourse, the International Tennis Federation, Fitbit and Rapha Racing.

On joining CRS, Couchman will take over as head of sport from partner Jason Saiban, who has been serving in the role since last year's departure of practice co-heads Ian Lynam and Jonathan Ellis.

Following the arrival of the Couchmans team – which also includes two further members of staff – CRS's sports practice will have a total of 13 partners and 20 fee earners.

The tie-up comes not long after both firms saw teams of partners leave to launch rival boutique offerings.

Lynam, Ellis and fellow sports partners Jon Walters and James Eighteen left CRS last October to launch new boutique Northridge, while the same month, Couchmans saw partners Dan Lowen and Fraser Reid leave to launch London practice LEVEL.

CRS managing partner James Carter said: "We are delighted to join forces with Couchmans. CRS has been at the forefront of providing legal advice to the sports sector for more than 100 years and has acted in many of the leading cases and projects that have helped to shape what is now known as sports law. The addition of the market-leading Couchmans team is a bold and innovative step forward for both firms and creates what we believe will quickly become the pre-eminent international sports sector legal practice.

Couchman added: "CRS provides the perfect platform for us. Both firms are immersed in this sector and have a track record of innovation and working on groundbreaking projects. We intend to set a new standard for sports law firms, not just in the UK, but internationally."

The merger comes four years after the combination of legacy firms Charles Russell and Speechly Bircham. Last year, CRS announced an 8% jump in profit per equity partner from £393,000 to £426,000, while revenue grew 3% from £140m to £144m.