Though comparable figures are hard to come by, a cloud-computing company reports that Amazon has a big lead in cloud computing, while Microsoft has a strong and growing hold on second place.

Share story’s cloud-computing unit is still a world beater. Microsoft is doing its best to entrench itself in second place.

Among companies that tap into the “public cloud,” or pooled servers and data-storage units accessed via the Internet, 57 percent reported using Amazon Web Services (AWS). Microsoft’s cloud-computing platform, Azure, was a distant second at 12 percent.

That’s according to RightScale, a Santa Barbara, Calif., company that helps information-technology departments manage their use of cloud-computing services. The company Wednesday released the results of its survey of 930 of corporate-technology experts.

The report is the latest data confirming the dominant position Amazon holds in the burgeoning market to sell Web-based computing power and storage. For the online retailer, the cloud-computing business has become so significant that it plans to detail the unit’s financial results for the first time in quarterly earnings reports this year.

The Seattle company was years ahead in building the software and server farms and other infrastructure that underpin the cloud, launching AWS in 2006. Microsoft introduced Azure two years later.

Both companies have since spent billions of dollars building the infrastructure powering everything from Web-based email to corporate clients’ databases and software-development tools.

In its bid to close the gap with Amazon, Microsoft has leaned on its existing relationships with businesses. The bulk of corporate-technology departments already buy Windows, Office, server products or something else built by Microsoft.

Representatives of Amazon and Microsoft declined to comment on the survey.

In an emailed statement, Microsoft spokeswoman Andrea Carl said Azure was adding 10,000 customers a week, repeating a figure the company originally released in October.

Both Microsoft and Amazon have limited the specific figures they disclose about the reach of their cloud-computing groups. Amazon, for instance, told The Seattle Times last month that AWS had more than 1 million customers, but declined to share its sales or growth rate.

There are at least two bright spots for Microsoft in RightScale’s data. The share of respondents using Azure was double the 6 percent share the service had when the survey was conducted a year ago. Azure’s platform as a service (PaaS) product, which is primarily used by developers to write programs and build websites, was the fourth most widely used cloud service, behind San Antonio-based Rackspace.

The industry divides cloud-computing products into three broad categories with unwieldy acronyms. PaaS, infrastructure as a service (IaaS), or the plumbinglike services such as data storage and server-processing power, and software as a service (SaaS), which refers to Web-accessed software like Microsoft’s Office 365 productivity suite and’s customer relationship management software.

RightScale’s survey shows Microsoft is making progress among large businesses. Among companies with more than 1,000 employees, 19 percent reported using Microsoft’s Azure IaaS, and 15 percent used Azure’s PaaS. That’s up from 11 percent and 12 percent, respectively, a year ago, but well behind Amazon’s 50 percent share.

RightScale’s survey also documents companies’ increasing acceptance of cloud-accessed servers as replacements for some of their own hardware. Fully 90 percent of respondents said their companies were already using some form of cloud services or planning on it.

Still, the survey, conducted by a cloud-computing management company, may represent a group of more eager adopters of new technology than the corporate universe as a whole.