Concerns have been raised by the Office of Fair Trading (OFT) over the fact that some firms already own a large share of contracts, and public-sector organisations faced large switching costs, in addition to higher barriers of entry.
The report will be tailored around assessing commercial software awards, in addition to outsourced IT services.
According to Reuters, the services between them accounted for half of the £13.8 billion public-sector IT spending in Britain in 2011/2012.
Reuters named HP, Capita, CapGemini, Fujitsu and BT as the top five IT suppliers in the UK.
The OFT could refer the results of its findings to the Competition Commission, which could mean action against the companies involved and state bodies.
