Tesco Bank has instructed A&O

Tesco Bank has turned to Allen & Overy for advice on its latest multibillion-pound sale – an unexpected move given the company's close ties to Magic Circle rival Freshfields Bruckhaus Deringer.

The bank – wholly owned by supermarket giant Tesco – is looking to offload its mortgage unit to Lloyds Banking Group in a £3.7 billion deal, with A&O advising the sellers according to a person with knowledge of the deal. A second person said Freshfields was not involved.

It is not known to what extent A&O has previously acted for either Tesco or its banking arm. The multinational groceries chain has long had ties with Freshfields, which has advised the company on its biggest mandates of the past few years.

Last year, Freshfields represented Tesco Bank after the Financial Conduct Authority fined it £16.4 million following a 2016 cyberattack. The Fleet Street firm also advised the wider corporate on its acquisition of wholesale food producer Booker Group, as well as on its alliance with French retail group Carrefour.

Freshfields represented Tesco on its protracted Serious Fraud Office investigation, in which the company agreed to pay a £129 million fine.

Tesco Bank has offered mortgages since 2012 and serves more than 23,000 customers across the U.K, according to one of its press releases from earlier in the year.

It is not yet known which firm is advising Lloyds. Firms on the bank's panel include Herbert Smith Freehills, Hogan Lovells, Linklaters and Ashurst, as well as A&O.