Amazon Web Services is the unstoppable force in public Cloud and has rivals left IBM, Microsoft and Google in its wake.

New third quarter data from Synergy Research Group shows that the three global IT gians -- IBM, Microsoft and Google -- continue to lag far behind AWS in the Infrastructure as a Service (IaaS) and the Platform as a Service (Paas) Cloud markets.

News and Slideshows on Microsoft

This is despite all of them achieving strong growth and IBM's acquisition of Softlayer.

According to Synergy, even after adding the PaaS revenues of Salesforce.com, in aggregate the group lags some 15 per cent behind AWS in terms of IaaS/PaaS revenue.

In a worldwide market that grew 46 per cent from the previous year, AWS grew by 55 per cent.

Total IaaS/PaaS revenues for the quarter passed $2.5 billion, with IaaS accounting for 64 per cent. North America accounted for 53 per of the second quarter market, with Europe the Middle East and Africa, and APAC each accounting for 21 per and Latin America 5 per cent.

Amazon is the clear market leader in each of the four regions, though the ranking of the chasing pack does differ by region.

Associated infrastructure service markets all grew in the quarter, but much more slowly than IaaS and PaaS.

Managed hosting revenues grew by 3 per cent year on year.

Synergy Research Group analyst John Dinsdale said the positioning of the leaders had not change much over the year.

"While Amazon dwarfs all competition, the race is on to see if any of the big four followers can distance themselves from their peers" he said

"The good news for these companies and for the long tail of operators with relatively small cloud infrastructure service operations, is that IaaS/PaaS will be growing strongly long into the future, providing plenty of opportunity for robust revenue growth."