The founder of the stadium and rock concert security firm Rock Steady has sold the business he set up 28 years ago.

Mark Hamilton, chairman and majority owner of the Edinburgh-based firm, has joined other shareholders in agreeing a deal with the security group G4S.

The group provides security for pubs and clubs as well as stewarding for sports events and concerts. Among its clients is Sheffield Arena, and Hamilton also headed up security for 2005's Live 8 events.

In its last financial year, the Rock Steady group turned over £12.2m. The buyout will see Rock Steady rebranded as G4S, with Hamilton staying on as managing director for a new division.