In a joint statement, telecoms billionaire Xavier Niel, investment banker Matthieu Pigasse and entrepreneur Moez-Alexandre Zouari said they were prepared to invest their funds in Casino to find a lasting solution to the group's financial woes.

This new money would come in the form of a dedicated vehicle, dubbed "3F" (founders, friends & family), that would be invested in a potential share sale of Casino, a source close to the matter said.

Starting with 300 million euros, 3F will seek to raise money from Casino's creditors to bring the sum to a little over one billion euros, the source added.

Casino had a consolidated net debt of 6.4 billion euros at the end of last year. It faces 3 billion euros' worth of debt repayments in the next two years and the holding company through which veteran entrepreneur Jean-Charles Naouri controls the company is also heavily indebted.

Amid mounting concerns about its ability to pay back its debts, Casino had been weighing a tie-up proposal from Teract and a rival one from Czech billionaire Daniel Kretinsky.

But Teract and Casino said on Thursday they had decided by mutual agreement to end exclusive talks started since March to combine the two group's retail activities in France.

Last month Casino, which owns the Franprix and Monoprix chains, officially started court-backed negotiations with its creditors.

In April, Kretínsky, already Casino's second-largest shareholder, offered to take control of Casino through a 1.1 billion euro ($1.18 billion) capital increase.

Kretinsky's proposal is backed by investor Marc Ladreit de Lacharrière, whose Fimalac group is now Casino's third-largest shareholder.

Casino said on Thursday the end of the discussions with Teract had no impact on a protocol of intent Casino announced last month with French rival Groupement Les Mousquetaires and which entails the sale to Les Mousquetaires of Casino stores in France, representing around 1.05 billion euros in sales.

($1 = 0.9316 euros)

(Reporting by Dominique Vidalon; additional reporting by Mathieu Rosemain and Gus Trompiz, Editing by Susan Fenton and Silvia Aloisi)

By Dominique Vidalon and Mathieu Rosemain