The future of Transgrid and Electranet's massive Project Energy Connect transmission project is in doubt after the Australian Energy Market Commission (AEMC) formally rejected a request from network companies to allow for increased early revenues from key network upgrades.

Transgrid believes the AEMC decision not only affects its project, but that it will impact other projects in the National Electricity Market that are not financeable under the current rules, because the projects would be rated sub-investment grade and not meet the Australian Energy Regulator's own rate-of-return requirements.