The compatibility suggests that AOL may be on its way toward creating a worldwide instant messaging system with 138 million potential users.
Numerous systems are already interoperable.
The FCC is considering forcing AOL to open up once it combines its system with ICQ or within six months of the merger, whichever comes first. AOL, which has an interest in remaining closed for as long as possible, has told regulators it isn't ready to open Instant Messenger to competitors and so far hasn't provided a time frame for when it would be ready. AOL argues that it wants to make its service work with competitors', but that it is concerned how that may affect the security and privacy of its users. AOL is working with an industry group to create a standard way for different instant messaging services to communicate. The spokeswoman said the capability is a byproduct of a test being conducted by engineers as it explores how to make its systems interoperate with others.