The chief executive of Algeria's Sonatrach state energy firm, Nourredine Cherouati, is to be replaced after 18 months in the job, three government sources told Reuters on Thursday.
A spokesman for Sonatrach declined to comment.
Two of the sources, who all spoke on condition of anonymity, said that Cherouati would be replaced by Abdelhamid Zerguine, a former Sonatrach vice-president for pipelines.
The same two sources said the change would be officially announced later on Thursday. "He (Cherouati) will be replaced," said one of the sources.
Cherouati was appointed in May 2010 after the previous chief executive, Mohamed Meziane, was removed as part of a judicial investigation into corrupt practices in the awarding of contracts to Sonatrach suppliers.
Cherouati gave a briefing to local media on Wednesday at which he denied speculation he was to be fired. Newspapers quoted him as saying the changes he was pushing through were upsetting certain people and interests.
The appointment of the chief executive of Sonatrach -- which controls energy exports from Algeria and partners foreign firms in all the country's oil and gas projects -- is the prerogative of President Abdelaziz Bouteflika.
One energy official said that Zerguine could be installed as a caretaker CEO until a permanent replacement was found.
Zerguine is 61 and is currently head of a Sonatrach subsidiary based in Switzerland. He has been in the company for over 30 years and also served as an adviser to one of Sonatrach's previous chief executives.