The letter is the latest attempt by two CMGI-owned companies, iCast and Tribal Voice, to bring the issue of instant messaging interoperability to the attention of regulators. As previously reported, the companies have been trying to solicit industry support from companies such as Excite@Home and Yahoo.
The companies also filed a complaint in April with the Federal Communications Commission asking officials to "encourage" AOL to open its network.
Now, the efforts to rally the industry seem to be paying off. The coalition of companies has sent a letter to the Federal Trade Commission and the FCC asking them to support interoperability for instant messaging.
Among the companies that signed the letter were Microsoft, Excite@Home, AltaVista, Fujitsu Laboratories of America and DynamicSoft.
Instant messaging has been a contentious market. Technology companies allege that AOL has not kept up with its promises to help develop an instant messaging standard. Companies arguing against AOL say instant messaging, like the telephone, is a communications vehicle that should be open regardless of technology.
"As IM continues to utilize content created by companies such as Time Warner, the potential merger raises even greater concern about AOL blocking their users from access to non-AOL users," Margaret Heffernan, chief executive of iCast, said in a statement. "We simply cannot allow AOL to stifle innovation and hinder interoperability."
AOL spokeswoman Tricia Primrose said the company has supported the widespread adoption of instant messaging throughout the industry and continues to support interoperability. She pointed out that AOL has opened its service to outside providers--including IBM, Novell, Lycos, EarthLink, Apple Computer and Juno Online Services--through licensing agreements. These partners can use AOL Instant Messenger (AIM) technology to create their own branded, or co-branded, software to offer customers.
AOL boosted its AIM service to include 91 million registrants in its "Buddy List" network. AOL also owns ICQ, the second-most-popular instant messaging product, with 62.4 million registered users. Both AIM and ICQ are proprietary systems that require people to download the software.
Some companies developing their own instant messaging software have tried to tap AOL's extensive network without hammering out a licensing agreement first. Companies such as Microsoft and Tribal Voice have made unilateral attempts to tap into AIM's servers to communicate with people on AOL's Buddy Lists. AOL, however, has reacted by blocking those companies' efforts, criticizing the unauthorized attempts as akin to "hacking" into its servers.
In the meantime, several companies, including AOL and Microsoft, have supported the adoption of an instant messaging standard overseen by the Internet Engineering Task Force (IETF), an Internet standards body. But participants have criticized the IETF for dragging its feet and AOL for showing tepid support for the standard. Some, such as Yahoo, are looking to establish their own standard.
AOL's Primrose said the company has been hesitant with proposals spearheaded by other companies because they were lax on consumer security and privacy. She said the "quick-fix approach" to developing a standard has not been something AOL could support.
"We think that right now it's worth it as a collective group in the industry to spend time to make sure we get interoperability right rather than fast-tracking a proposal that puts consumers at risk," Primrose said.
Companies vying for access to AIM's network are turning up the heat in their lobbying efforts. While they do not support regulation of instant messaging, they are asking regulators to take a closer look at the issue.
"For the government to support the principle of open standards does not require that the government regulate or set the standard," the letter read. "But the government should make it clear to the marketplace its expectation that no single provider will be allowed to put a wall around the market, either to keep their customers in or to keep competition and innovations out."
The letter comes after AOL has offered to make concessions to the European Union in an attempt to win approval of its acquisition of Time Warner. Both the United States and the European Union must approve the merger for it to go through.
The Associated Press contributed to this report.