Tokyo Gas Company and Mitsubishi Corporation have taken the stake through Trinity Gas Resources Pty Ltd, which leaves OMV with 35%. Santos holds the remaining 35%.
The field is expected to come on line in 2005 with Tokyo Gas saying it expects to put at least $85.2 million into the project.
Gas from the 5bcf Sole gas will be processed at OMV's Patricia Baleen gas plant, located onshore Gippsland in Victoria.
Mitsubishi controls Trinity Gas, with a 75% stake.