Confirming recent comments by Microsoft CEO Steve Ballmer, an independent study released Friday found OpenOffice.org's free office suite to be five times more popular among adult US internet users than Google Docs.

Microsoft Office remains dominant, with 51 percent of American internet users over age 18 using it, according to a 6-month study conducted by market researcher ClickStream Technologies.

OpenOffice.org was used by 5 percent of people, versus Google Docs' 1 percent, according to the survey of 2,400 users on their home PCs conducted between May and November of this year. OpenOffice.org was also found to be used more often, 8.7 days, versus 1.5 days; and longer, an average of 9.3 minutes, versus 3.4 minutes for Google Docs, according to ClickStream's panel, which was two-thirds comprised of women.

During a keynote speech at a Gartner conference last month , Ballmer said: "We have better competition today than Google Docs and Spreadsheets. We get more competition from OpenOffice and StarOffice, frankly."

Microsoft is poised to cement that domination with its upcoming Office Web , and online versions of its Exchange and SharePoint products, to be announced this week.

The latest version, OpenOffice.org 3.0, had a strong first week, with more than 3 million downloads in that time. After one month, OpenOffice.org 3.0 had been downloaded 10 million times, the group said.

ClickStream also found that 68 percent of Google Docs or Spreadsheets users also used Microsoft Word at least once, "indicating that Google Docs has yet to be considered a stand-alone product by most of its users."

In contrast, 74 percent of OpenOffice users didn't use Word at all.

"Although Google Docs and Spreadsheets has been touted as a potential competitor to the Microsoft Office Suite, OpenOffice is currently the more likely app to take that position, possibly indicating the value of offline and local processing enabled by installed applications," said ClickStream.

A Google spokesman said in response to ClickStream's finding, "Google Docs has millions of active users and hosts tens of millions of documents. It has seen strong and steady growth since it launched two years ago as people have increasingly shifted to the cloud in order to access and collaborate on documents online."