Security company GardaWorld has tabled a possible offer to buy G4S for £2.96 billion, but its approaches have been ignored.
The Canadian giant approached G4S three times between June 15 and August 31.
It added: “GardaWorld’s attempts to engage with G4S’s board have now been summarily dismissed or ignored on three occasions.
“Consequently, GardaWorld now encourages G4S’s shareholders to mandate their board’s engagement in collaborative discussions towards a transaction that would be of clear and immediate benefit to G4S’s shareholders, customers, employees and members of the company’s pension schemes.”
GardaWorld boss Stephan Cretier said: “G4S needs an owner, not a manager. GardaWorld has 25 years of experience in the sector and we know how to improve and repurpose this business.
“As owner-operators, we believe that the combined business’s operations will offer a better future for all those who depend on G4S. We will turn G4S around, ensuring it delivers for its customers, its people and the public.
He added: “We understand G4S’s importance as a UK employer and as a significant provider to public and private sector institutions. In addition, significant steps would be taken to address the company’s persistent underfunding of UK pension obligations.
“Our valuation offers a certain path for G4S’s shareholders to immediately recover lost value. We encourage shareholders to ask G4S’s board to begin engaging with us.”
G4S shares were up 23% or 32.8p at 179.2p.