But Amazon, Microsoft and Yahoo, all members in 2006 of the group's predecessor, the It's Our Net Coalition, have not joined the new entity. It's Our Net reportedly had 172 participants, but its successor has less than a third of that, despite a broader agenda that includes supporting widespread deployment of broadband service.

Microsoft dropped out of It's Our Net last fall because the organization wanted to impose neutrality regulations on the merger of AT&T and BellSouth. Microsoft's policy is not to intervene in such transactions. The software firm had said its departure was temporary, but it never returned to the coalition, which eventually disbanded and reorganized into the association announced Thursday.

Microsoft officials were not immediately available for comment, but in April, spokeswoman Ginny Terzano told Technology Daily that the firm remains committed to an accessible and open Internet whether it rejoins or not.

Amazon Vice President Paul Misener said: "Don't read this to be any diminution of our support for net neutrality. We're outspoken about it." He noted that Amazon joins and leaves various associations all the time, and he insisted that "there is no change in our position [supporting] net neutrality."

Yahoo officials also could not be reached for comment.

"We think that as the coalition begins to build with this broader agenda focusing on what is going to be necessary to have a healthy, vibrant, competitive Internet, that more and more organizations and companies are going to join us," Markham Erickson, executive director of the Open Internet Coalition, said in an interview.

Google Chief Executive Eric Schmidt said in April that while the search engine supports Internet regulation, Google would flourish without it because it is well-positioned to cut deals with broadband providers.

EBay Chief Executive Meg Whitman is a fundraiser for Republican presidential candidate and former Massachusetts Gov. Mitt Romney, but he has not publicly discussed the issue. EBay has said Whitman's position with Romney's campaign does not reflect the online auctioneer's stance.

While net neutrality advocates scored a victory last year when major telecom legislation considered weak on safeguarding Internet competitors was derailed, no federal action to mandate tough safeguards has occurred this year.

On Thursday, the Open Internet Coalition sent a letter to all members of congress, urging them to adopt a national broadband policy that would promote the rollout of affordable high-speed Internet service to more Americans. Erickson noted that Amazon signed the letter even though it has not joined the organization.