The deal was signed in 2021 for TotalEnergies to build four oil, gas and renewables projects with an initial investment of $10 billion in southern Iraq over 25 years.
But it has experienced several setbacks amid disputes between Iraqi politicians over terms.
Iraq's demand for a 40% share in the project was a key sticking point as TotalEnergies wants a majority stake.
The agreement to lower the share to 30% was struck after meetings in Baghdad over the past few days, an industry source said.
TotalEnergies did not immediately respond to a request for comment.
"The deal should be activated within days," a senior Iraqi oil ministry official said.
(Reporting by Ahmed Rasheed, Maha El Dahan and America Hernandez; Editing by Kirsten Donovan)
By Ahmed Rasheed and Maha El Dahan