Securicor says it is in talks on a merger with Denmark's Group 4 Flack over a deal that would step up competition to the world's number one-ranked security firm Securitas.
Shares in the combined firm would be listed in London and Copenhagen. Group 4's safety and rescue and global solutions businesses would be demerged prior to a deal and listed in Copenhagen.
"Discussions are at an early stage and there can be no assurances that any agreement will be reached," Securicor said in a brief statement.
Securicor's shares closed at 112 pence on Friday, valuing the business at around £595 million sterling. Shares in Group 4, the world's second-biggest security services firm, closed at 130.5 Danish crowns, valuing it at about 11.6 billion Danish crowns.
The combined firm, even before the demerger of some of Group 4's businesses, would be smaller than Sweden's Securitas, which has a market value of about £2.5 billion.