Royal Bank of Scotland may face further legal action over a £12 billion rights issue.
A group of around 16,000 shareholders who say they lost money in the 2008 exercise, just before the bank's collapse, have already launched a compensation claim against RBS and several of its former directors.
A preliminary hearing at London's High Court before Mr Justice Hildyard has heard that units of Legal & General Group plc, Prudential plc and Standard Life plc were considering joining the existing litigation or filing new claims.
RBS is now mainly taxpayer-owned after it was bailed out by the government to the tune of £45.5 billion.
If a full hearing of the case goes ahead, former RBS chief executive Fred Goodwin, who was not in court today, is among those likely to give evidence.
A further case management hearing is expected to take place in January.