Michael Potts, a lawyer with Byrne & Partners, said his client Paresh Shah had been charged earlier on Wednesday and further charges were expected.
"There will be seven others charged today," Potts said. He declined to say how Paresh would be pleading but said he did not think that any of the accused had agreed to testify against others in return for immunity from prosecution.
The charges in the investigation, codenamed Saturn, come almost two years after authorities arrested eight people during raids on properties in London and south east England.
Other industry sources have said the suspects include a sub-contractor at Cazenove, now owned by US investment bank JPMorgan Chase & Co., and a junior employee at UBS AG. The Financial Services Authority (FSA) declined to comment and no further details were immediately available.
But the regulator, which has been hitting the headlines after a series of sting operations to pursue market abuse, was expected to lay charges on Wednesday because the suspects had been bailed until end-March, another industry source has said.
Last week, a squad of almost 145 FSA officers teamed up with a specialist police unit to arrest seven bankers and traders after seizing documents and computers at 16 business and residential addresses in what the regulator called its largest operation against insider dealing to date.
The FSA, which is increasingly keen to use its criminal powers to pursue market abuse, has jailed five people since 2009 - although one person received a suspended sentence - and is prosecuting three other cases.
