NYSE Euronext Chief Executive Officer Duncan Niederauer said European regulators’ analysis of its takeover by Deutsche Boerse AG is “fundamentally flawed,” and vowed to fight to complete the deal.

“Their assertions are that the derivatives industry is not global and that the over-the-counter and exchange-traded derivatives markets are not converging and therefore do not compete,” he said in the transcript of a presentation to employees obtained by Bloomberg News. “That’s a conclusion that results from a fundamentally flawed technical analysis that ignores the realities of the marketplace.”

Niederauer is meeting with his counterpart at Deutsche Boerse, Reto Francioni, in New York today as they seek to overcome opposition to their plan for building the world’s biggest exchange operator, according to two people familiar with the matter. Concessions offered by the two exchanges didn’t go far enough for European Commission staff to approve the merger, negotiators informed the companies at a Dec. 21 meeting in Brussels, two people familiar with the talks told Bloomberg at the time.

The companies still have room to maneuver. Commissioners from each European Union country vote on a final decision after receiving the case team’s advice, which is non binding.

“We’re going to continue to press our case directly with various Commissioners in the EU,” Niederauer said in the presentation. “Both to highlight the serious flaws in the case team’s core argument, and to ensure that there is a clear understanding of the strong benefits that our combination will bring.”

Niederauer and Francioni have been working since February to convince authorities that their agreement won’t stifle competition in derivatives trading. Topics of today’s meeting will include opposition in the European Commission and among regulators in the German state of Hesse, according to people familiar with the situation.