The deal provides an exit for venture capitalist Foresight, generating a return of 4.4 times its original investment.

Foresight backed Covion’s management buy-out in 2005, investing £2.5 million from Foresight VCTs 1, 2, 3 and 4. This is the fourth exit this year for the firm.

Donald Maclennan, partner at Foresight, comments: ‘Covion’s business has prospered, attracting several new high-profile customers such as Britvic’s UK estate, Domestic & General, Archant and Tate & Lyle, and significantly increasing turnover.’

Covion is to become part of Haden Building Management, Balfour Beatty’s existing facilities management arm, and will add a number of private sector clients to Haden’s predominantly public sector portfolio. The acquisition will also enhance Haden’s technical expertise, according to Balfour Beatty’s chief executive Ian Tyler.

Founded in 2000 and based near Reading, Covion offers its clients a package of services which include telecoms network maintenance, estate management, payroll and staffing services, cleaning, security and catering. It has some 600 employees and its revenues for this year are expected to exceed £33 million.