Linden Lab, creators of Second Life, has developed a set of compatible avatars with IBM that can be used on either company's systems.
The pair claim to have successfully transported avatars from IBM's OpenSim virtual world server to a Second Life preview server.
The 3D characters were 'teleported' from one server to another and were able to function in both worlds.
IBM and Linden Lab said that the occasion marks an "important milestone" in their interoperability efforts.
Both companies have been looking for new avenues for virtual worlds. Linden Lab is hoping to extend the reach of Second Life, while IBM has long been looking to 3D worlds as a vehicle for its business and communications programmes.
The plan is to create a system in which a user can create a single avatar that can be transported and used in a variety of virtual world platforms and servers.
The companies also hope to create a system to make 3D worlds practical for use by businesses for internal and public events.
"Interoperability is a key component of the 3D internet and an important step to enabling individuals and organisations to take advantage of virtual worlds for commerce, collaboration, education, operations and other business applications," said Colin Parris, IBM's vice president of digital convergence.
"Developing this protocol is a key milestone and has the potential to push virtual worlds into the next stage of their evolution."
Facebook told by Brussels-based court to stop tracking non-users and to delete all data held on them
Supply chain and manufacturing experience could give Dyson an important edge
New VR Zone Portal arcades open in London and Tunbridge Wells
Systems-on-a-chip with integrated AI features could make voice and facial recognition