Groupe Casino has been beset with debt following a string of acquisitions and by declining revenues in a competitive domestic market.
In May, the company started court-backed negotiations with its creditors, while weighing two tie-up bids from wealthy investors.
The agreement with the government would help Casino to preserve its liquidity throughout the conciliation procedure with creditors opened on May 25.
The agreement represents an amount of around €300 million.
The company also said all the financial creditors would be asked to agree, for the duration of the proceedings, to a standstill on any interest payments and other fees and principal instalments owed over this period by the group companies benefiting from the negotiations.
Separately, French markets regulator AMF said in a filing that one of Casino's top investors, billionaire Marc Ladreit de Lacharriere, had become Casino's second-biggest shareholder.
Ladreit de Lacharriere, 82, now owns about 12% of the French retailer after the businessman agreed to convert bonds issued by Casino's controlling holding Rallye into shares, the filing said.
The billionaire previously owned 2.65% of Casino, based on Refinitiv data. Rallye, controlled by veteran entrepreneur Jean-Charles Naouri, is Casino's majority-owner.
Ladreit de Lacharriere recently joined Czech billionaire Daniel Kretinsky in a €1.1 billion bid for Casino. Kretinsky is now Casino's third-biggest shareholder with a 10% stake.