The organising committee's (Cojo) budget for the 2024 Paris Olympics needs to rise by about 10 per cent, or 400 million euros (411 million dollars), half of that due to inflation, the body said on Tuesday.
Cojo are due to finalise the budget at a board meeting on December 12.
The estimated cost of the Paris Olympics and Paralympics has risen from an initial 6.6 billion euros, after the city was awarded the Games in 2017. That total was split equally between Cojo and Solideo, the public company in charge of building projects.
By this summer, the total had risen to 8 billion, with Cojo's share at 4 billion.
Cojo does not receive money from the French government, which makes its contribution through Solideo.
"We are in the final stages of this budgetary closure," Fabrice Lacroix, Cojo's chief finance officer, told a press briefing at the end of an executive committee meeting.
Lacroix said that Cojo was on course to hit its target of raising 1.1 billion euros from local sponsorship.
Cojo also said that ticket sales, which represent a third of anticipated revenue, should exceed the 2021 target of 1.265 billion euros.
The rest of Cojo's revenue comes from the International Olympic Committee.