The Khrunichev space company announced the completion of the Nauka ("Science") module Friday, RIA Novosti reported.
The completed module will be sent to the RKK Energia Corp. for testing, the company said.
"Work has been completed on assembly of the multirole laboratory module for the International Space Station. The module was sent to RKK Energia on December 7 for further electronic testing of the flight systems," Khrunichev said.
The ISS is equipped with five Russian built modules: the Zvezda service module, the Zarya cargo block, the Pirs docking module and the Poisk ("Search") and Rassvet ("Dawn") research modules.
The Nauka module was to have been launched on a Russian Proton rocket in 2011 but the project has suffered numerous delays.
The Nauka will eventually be attached to the Zvezda module, RIA Novosti reported.