LONDON (Reuters) - British private equity group Charterhouse Capital Partners
G4S, the world's biggest security firm, declined to comment and Charterhouse was not immediately available to comment on the report.
Charterhouse approached banks and its investors over financing a deal for the unit, which transports cash using high-security vehicles and manages ATM machines, according to three people familiar with the matter.
G4S is aware of the proposal and discussed the sale option internally, said one of the sources, but it may decide against a sale of the unit, according to the report.
($1 = 0.6178 British pounds)
(This version of the story corrects the headline to say $1.6 billion not £1 billion.)
(Reporting by Lorraine Turner; Editing by David Cowell)