PARIS (Reuters) -Atos shares plunged on Monday after calls from opposition lawmakers for the nationalisation of the ailing IT firm on national security grounds raised doubts about a planned deal involving Czech billionaire Daniel Kretinsky.
The stock, which since late 2017 has lost 97% of its value, fell by up to 12% to hit its lowest in more than 20 years.
Two lawmakers - Olivier Marleix from the conservative Les Republicans and Socialist Philippe Brun - both lodged amendments to France's 2024 budget bill for a temporary state takeover of Atos, citing a threat to France's sovereignty.
"We cannot allow a foreign company to take control of these activities, which are absolutely essential to our national independence", Philippe Brun said in a post on X, formerly Twitter.
Asked by Reuters if the government was considering nationalisation, or could support an amendment to do so, a finance ministry source replied "no".
Earlier this month, Atos appointed former UniCredit CEO Jean-Pierre Mustier as chairman as the company sought to reassure investors it will manage a successful turnaround, involving the sale of its IT outsourcing unit to Kretinsky.
The deal would also give Kretinsky a 7.5% stake in the remaining business, dubbed Eviden, that includes the lion's share of those Atos assets viewed as potentially strategic, such as cybersecurity and supercomputing.
The approach by Kretinsky, a well-known figure in France whose investments in the country range from media to retail, sparked protests across France's political spectrum.
Lawmakers from Les Republicains said the deal threatened to allow French supercomputers, made by Atos and used for virtual nuclear tests, to fall into foreign hands.
Others, including Brun, have said critical Atos components were also used in combat systems used by France's navy and air force. Atos had also won a contract to process data for the Paris 2024 Olympic Games.
The Les Republicains amendment suggests earmarking 500 million euros for the nationalisation, whereas the amendment from the socialist lawmakers, pursuing a narrower approach of only nationalising two Atos units, would lead to a cost of 390 million euros.
The amendments so far have not been adopted by the National Assembly and would likely need to be backed by the government, which is expected to use special constitutional powers to push through the 2024 budget bill without a final parliamentary vote.
($1 = 0.9439 euros)
(Reporting by Leigh Thomas and Mathieu Rosemain; Writing by Tassilo Hummel; Editing by David Holmes)