Amazon Web Services retained its dominant status in the cloud infrastructure services market, according to a recent market report by Synergy Research Group. Salesforce dominated Platform-as-a-Service (PaaS).

Amazon's market share in Infrastructure-as-a-Service (IaaS) was more than 35% in the fourth quarter of 2012, Synergy estimated. The second-highest market share belonged to IBM but was only about 5% of the market, followed by British Telecom with under 5%.

Amazon was slightly behind Salesforce in the PaaS space, which had about 20% market share. Behind Amazon was Microsoft, which had about 15% of the market.

“Thanks to its significant market share in the high-growth Infrastructure-as-a-Service and Platform-as-a-Service (PaaS) segments, Amazon continues to lead the cloud infrastructure services market,” Synergy's partner TeleGeography said in a statement.

Total revenue generated by cloud infrastructure services grew 15% over the course of 2012, reaching US$12.5bn for the year, according to the researchers. While IaaS and PaaS segments make up only 15% of the overall infrastructure-services market, both are growing at a much greater pace than the rest of the segments.

Synergy included Content Delivery Network (CDN), colocation and managed hosting services in its analysis. Combined, managed hosting and colocation make up 74% of the total market, TeleGeography said.

Akamai lead the CDN market, followed by Level 3 and Amazon, according to the report. Equinix had the lead in colocation, with more than 10% market share, followed by Savvis and SunGard.

Rackspace had the largest market share in managed hosting (about 5%), with Verizon and NTT following closely, according to Synergy.

John Dinsdale, of Synergy, said the developing battle for market share was fascinating.

“Traditional telcos are strong in the more mature managed hosting segment, where they account for eight of the top ten operators, but their impact on the IaaS and PaaS segments has so far been muted,” he said. “We have no doubts that they will more aggressively target those segments in the coming years.”