Airbus SE (ENXTPA:AIR) has called off talks to buy the BDS cybersecurity unit of France's Atos SE's (ENXTPA:ATO), sending shares of the French software company tumbling 18% in early trading. It is the second time in a year that the European plane maker has axed proposals to buy assets of debt-laden Atos after it declined to make an offer for a minority stake in a broader business a year ago following a backlash from its own investors. Atos, which in January named its fourth new chief executive in less than two years, and saw talks over another potential sale collapse last month, has grappled with a series of profit warnings and is looking to raise funds to deal with its debt.

"Atos is analysing the resulting situation and actively evaluating strategic alternatives that will take into consideration the sovereign imperatives of the French state," it said in a statement. Airbus said it had taken the latest decision "after careful consideration of all aspects of a potential acquisition" of the big data and security activities. A person familiar with the matter said Airbus had pulled out of the BDS talks due to concerns over risk and the broader turmoil surrounding Atos.

Airbus declined to add to its brief statement over ending the BDS takeover talks. There was no immediate comment from the finance ministry or from Atos' leading shareholder, One point.