SIA-SSB group consists of a number of companies specialising in network services, card processing, payment systems and capital markets back-office and surveillance systems.

The company is currently majority owned by two Italian banks, Intesa Sanpaolo and Unicredit Group, with a number of other bank and telecom owners.

Last year it appointed Citi as an advisor to help it find parties interested in buying the company.

Atos Origin was one name on a shortlist of bidders, and hoped to merge SIA-SSB into its Worldline unit to become the European leader in the transaction processing business.

However, no deal was struck, with the Italian firm's shareholders reportedly holding out for a deal valuing it at around EUR600 million.

Citing sources familiar with the matter, La Tribune says Atos has rekindled its interest and is in exclusive negotiations over a deal worth between EUR350 million and EUR400 million.

SIA-SSB refused to comment on the fresh reports.