The 109-year old law firm Irwin Mitchell is exploring a £500m flotation that would make it the most valuable legal services business listed on the London Stock Exchange. The Sheffield-based full service law firm, which worked on high-profile personal injury cases including the Lockerbie Pan Am flight bombing, the Marchioness riverboat disaster and the coronavirus-related deaths of NHS workers, is exploring strategic finance options with the investment bank Rothschild. A stock market flotation is a relatively rare move for a legal firm. If Irwin Mitchell can achieve its intended valuation, first reported by Sky News, it will be the largest listed in London by a considerable distance. Rivals include DWF, with a market capitalisation of £282m, Knights Group (£359m) and Keystone Law (£195m). A listing for the firm, which employs more than 2,600 staff and signed up as the official legal sponsor of England Rugby two years ago, could result in a windfall for its 214 partners, who could become paper millionaires by converting their interests into shareholdings. “In a typical float, founders, investors and owners get a pay day,” said one city source. “On paper the law firm’s partners would own a percentage of a publicly listed entity, as they are the effective shareholders of the group. Their partner interests could become shares. But there would be lock-in clauses – it all depends on what’s in the prospectus.” In its annual report for the year to the end of April 2020, Irwin Mitchell said it employed 1,684 “fee earners” and 979 administration staff, and spent £110m on wages, salaries and pension payments. The chief executive, Andrew Tucker, a 36-year company veteran, was paid £661,000. In the report, published on 23 December, the company said that one of its aims was to seek takeover targets to expand the business. The report said: “The board intends to grow the key areas of the business through continued investment in the Irwin Mitchell brand, organic growth, in new talent and further merger and acquisition activity if opportunities allow.” Irwin Mitchell adopted what is known as an alternative business structure in 2010, which allows it to offer a wider range of services from its 15 UK offices. For example, the firm now has five licences to operate services that include debt collection, international assistance and insurance claims handling, trustee appointments and estate administration, and acting as a deputy from the Court of Protection. A spokesperson for the company said: “We’ve taken no decision to introduce external investment. We remain in a strong position financially with our existing bank facilities offering us sufficient firepower to invest further in the growth and transformation of our business.” Other law firms listed in London include Gateley, Ince Group and RBG Holdings, the parent company of Rosenblatt Solicitors. Mishcon de Reya, which has represented an array of famous clients including Princess Diana, has also considered going public in the past. Last summer, Irwin Mitchell said 110 jobs were at risk due to the pandemic, as it also took over provision of the official legal helpline and online document services for 1,500 England Rugby member clubs.