The top ten global IT outsourcing firms earned around $27 billion (15.5 billion GBP) in 2007, according to new research.

Studies carried out by IT industry analyst IDC found 64 per cent of this revenue was tied to discrete engagements and 36 per cent integrated within larger IT outsourcing contracts.

Rona Shuchat, director of application outsourcing services at IDC, said discrete and bundled application management (AM) service earnings reached an estimated $35 billion for the top 25 global service providers.

She added: “This reflects growing adoption of enterprise use of third-party providers, not only for standalone AM service but also for transformational value-added services linked into AM or broader bundled outsourcing solutions.”

Last week, online technology portal ITcontractor.com claimed the IT industry is on the verge of a downturn that could see an increase in the amount of work being outsourced.

Spokesman for the group Gerry McLaughlin said finance directors tend to outsource part or all of their IT capability after cutting contractor jobs.