Under the deal, Sefe would receive additional government-backed credit lines to help it honour a contract under which it supplies 65 terawatt hours (TWh) of gas to VNG - part of German utility EnBW - each year, the people said.
An agreement could be reached as soon as this week, one of the people said, adding talks were ongoing and the outcome could still change.
Germany's economy ministry, VNG and EnBW declined to comment. Sefe was not immediately available for comment.
(Reporting by Christoph Steitz, John O'Donnell and Holger Hansen; Editing by Mark Potter)