Atos issued a statement saying the move to buy DXC in what it said was a “friendly transaction” to create a digital services powerhouse with a global presence.

The French firm, led by chief executive Elie Girard, made a formal approach to DXC this week valuing the New York listed company at more than $10 billion including debt.

DXC said in a statement it had received a takeover proposal and had no prior knowledge of any interest from Atos. It called the offer “unsolicited, preliminary and non-binding”, adding its board of directors would evaluate it.

Shares in DXC, which is a former Hewlett Packard Enterprise business, were up 10 percent to $29.13 at 15:17 GMT, while Atos dropped 12 percent on the news, making it the worst performing stock on the Paris SBF-120 index.

Atos is working with advisers on the potential DXC bid, which would boost its US presence, giving it access to a wide range of clients and B2B products including analytics and cloud applications as well as IT outsourcing services.

If successful, a combination with DXC would lead to synergies and cost savings for Atos, which has been on an acquisition spree in recent years, the sources said.