JP Morgan is seeking approval to handle deals on the London Stock Exchange's Pisces market, in a further sign of growing momentum behind the private bourse.

The US bank is looking to join the likes of Bank of America and Rothschild in becoming a so-called registered auction agent, a status that would allow it to broker deals on the London Stock Exchange's Private Securities Market, sources told City AM.

The arrival of major global banks as intermediaries matters for the platform's traction: registered auction agents are the firms that connect shareholders looking to sell with buyers, so participation from institutions of JP Morgan's scale broadens the pool of capital and counterparties available to private companies using the market.

Pisces – the Private Intermittent Securities and Capital Exchange System – was introduced by the Financial Conduct Authority (FCA) last year to allow private companies to sell shares at structured auctions in a style resembling public markets. It forms part of a wider set of UK regulatory efforts to make London more attractive as a financial centre at a time when many high-growth companies are choosing to stay private for longer rather than pursue a public listing.

The framework, drawn up by the London Stock Exchange and the previous Conservative government, was designed to let investors and employees cash in their shares without the rigmarole of a public listing. Several private companies have since launched their own version of the market, including the London Stock Exchange and JP Jenkins.

A shot in the arm for Pisces?

JP Morgan's interest would be another boon to the fledgling bourse after a crop of deals from high-growth start-ups in recent months.

Wayve, the AI car firm, allowed its staff to sell around $85m (£62.8m) of shares on the market in July, in the first major employee share sale on the platform. Savings fintech Moneybox also ran a £45m staff share sale through the exchange later that month, which valued the company at £800m.

David Schwimmer, the boss of LSEG, the parent company of the London Stock Exchange, told investors in July there was "growing momentum" behind the market and that it was "opening up significant new market opportunities" for the group.

The summer deals followed a sluggish start for the Pisces framework, which was launched to much fanfare from the government but drew criticism from some advisers who questioned its usefulness.

Several people spoken to by City AM have raised concerns that the market could undermine the UK's efforts to revive its initial public offering pipeline by allowing firms to stay private for longer. How the balance between secondary liquidity for private shares and the UK's IPO pipeline plays out is likely to shape how policymakers and regulators assess the framework's success in the months ahead.

The London Stock Exchange has hosted just one sizeable IPO this year: the Uzbek national investment fund UzNIF, which raised $600m in a dual listing in Tashkent and London in May.

JP Morgan declined to comment. The London Stock Exchange also declined to comment.