Atom Bank is seeking fresh funding of £150mln from investors, according to a report by Sky News.
The digital-only lender, which has no physical branches and operates through a smartphone app, raised £30mln in November and is now looking to raise at least £100mln in equity, although it may seek as much as £150m, said one insider.
The challenger bank's fundraising talks come at a time when there are concerns about the banking sector following the collapse of Silicon Valley Bank and two other tech-focused lenders.
Atom is a leading proponent of the four-day working week.