LONDON (Reuters) - British security firm G4S (>> G4S plc) has held talks with large investors about the prospects for tapping them for cash, a spokesman for the company said on Sunday.

G4S CEO Ashley Almanza has ordered a sweeping review of G4S and is expected to announce measures to try and repair its balance sheet when he reports half-year results in August, the spokesman confirmed.

Asked about the possibility of a rights issue, Almanza told Britain's The Sunday Times newspaper: "Shareholders have been asked about this. I will conduct a full review of the business and evaluate the various options, and we have many options. I have not given any signal either way."

His comments follow a difficult week for the company.

Britain said on Friday it would not be awarding any new contracts to G4S and rival Serco (>> Serco Group plc) until they received a clean bill of health from a government review after an audit found they had charged for tagging criminals who were either dead, in prison or never tagged in the first place.

Shares in G4S, which makes around 10 percent of its turnover from British government work, have tumbled 25 percent over the past year amid a series of scandals.

Its reputation was severely hit last year when it failed to provide enough security guards for the London Olympics and a profit warning in May led to the departure of long-serving chief executive Nick Buckles.

(Reporting by Tommy Wilkes, editing by William Hardy)

Stocks treated in this article : Serco Group plc, G4S plc