Atos proposed a “friendly” deal on November 28 that would create a European leader in cyber security technology. The offer represented a 42 percent premium to Gemalto’s closing price on December 8, according to Atos. Shares in Gemalto soared 33.5 percent on Tuesday after Atos revealed its takeover offer.

Gemalto, said Atos’ offer undervalued the company.

A fund manager at Kiplink Finance, Philippe Cohen, told Reuters that traders expected Atos to sweeten the deal.

“Atos started with a low price, which is logical in this type of negotiations. There’s also the scenario of a ‘white knight’, probably French, such as Thales for example. But the most likely scenario for us is that Atos raises its offer”, he added.

In an interview with French daily Les Echos, Gemalto’s chief executive Philippe Vallee said Atos’s strategy for the group was “unconvincing” and “significantly” undervalued the company, but he did not completely shut the door on a deal.

“We had to respond to this offer”, Vallee told the paper.

Asked if Gemalto would reconsider its decision if Atos responded to their concerns, Vallee confusingly added: “Our answer is clear. I can’t foresee the future.”