Slaughter and May and Skadden Arps Slate Meagher & Flom are advising on the £3.24bn sale of Standard Life Aberdeen's (SLA) insurance business to FTSE 250 insurer Phoenix Group.

The unit being sold, Edinburgh-based Standard Life Assurance Limited, is one of the UK's oldest insurance companies.

Parent company SLA said it would receive £2.3bn in cash and a 19.9% stake in Phoenix as part of the deal.

Slaughters is acting for SLA with a team led by City corporate partner Jonathan Marks. The magic circle firm is working alongside SLA's in-house legal team, which is led by group general counsel Rushad Abadan and supported by Sara De Busk, head of general counsel's office, senior legal counsel Benjamin Brust and legal counsel Gayle Bacchus.

CMS conducted due diligence on behalf of SLA.

Slaughters previously advised SLA on last year's merger between Standard Life and fund manager Aberdeen Asset Management, which completed in August.

Meanwhile, Skadden is representing Phoenix with a London-based team led by private equity partner Robert Stirling, capital markets partner Danny Tricot, investment management partner Stephen Sims and tax partner James Anderson.

Freshfields also acted for Phoenix on debt finance matters with banking partner Sean Pierce.

Irish firm William Fry also played a role, acting for Phoenix on the Irish legal aspects of the deal with Dublin M&A partner Eavan Saunders in the lead.

Last year's merger of Standard Life and Aberdeen Asset Management also handed roles to Freshfields Bruckhaus Deringer and Maclay Murray & Spens, both of which advised Aberdeen. Maclays has subsequently completed a merger with Dentons.

The firms advising on that deal will share almost £16m in legal fees for their work on the tie-up, with Freshfields and Maclays dividing up the £7.5m in legal costs estimated by Aberdeen, and Slaughters in line for £8.1m generated by its work for Standard Life, according to a scheme of arrangement published last year.