Public cloud computing generated over $22 billion in revenues for IT companies in the second financial quarter of 2015, according to a study by Synergy Research Group.

The revenue breaks down into $10 billion earned by companies supplying public cloud operators with hardware, software and data centre facilities and $12 billion being generated from selling infrastructure, platforms and software as a service.

In addition the public cloud supports ‘huge’ revenue streams from a variety of internet services such as search, social networking, email and e-commerce platforms, says the report. It identifies the supply side companies with the biggest share of revenues as Cisco, HP, Dell, IBM and Equinix. On the cloud services side the market leaders are AWS, Microsoft, Salesforce, Google and IBM.

As the public cloud makes inroads into the total IT market, the hardware and software used to build public clouds now account for 24 per cent of all data centre infrastructure spending. Public cloud operators and associated digital content companies account for 47 per cent of the data centre colocation market.

While the total IT market grew at less than five per cent per year, the growth of cloud revenues outpaced it. Infrastructure and platform as a service revenues (Iaas/Paas) grew by 49 per cent in the past year and software as a service (SaaS) grew by 29 per cent.

“Public cloud is now a market that is characterized by big numbers, high growth rates and a relatively small number of global IT players,” said Synergy Research Group’s chief analyst Jeremy Duke.

However, the report noted that there is still a place for regional small-medium sized public cloud players.