Securicor PLC, unveiled a nil-premium merger with the world's number 2 security services company, Denmark's Group 4 Falck A/S, this morning.

CHUBB Plc, the British security company that is in talks to be acquired, may cost more than £1 billion (€1.4bn), limiting potential suitors to private-equity firms and companies as large as Rentokil Initial Plc, analysts say.