In the open letter, both the exchanges said Nyse Euronext’s management and board continue to deny that the Nasdaq OMX/ICE proposal is superior to the existing Deutsche Boerse agreement or that they have a fiduciary duty to review the proposal.

The letter added the board is ignoring corporate governance best practices and the market reality of the situation.

According to the letter, their proposal offers substantially greater short and long-term value and creates a compelling opportunity for the NYSE Euronext Board to meet with them while presenting no downside risk and only upside for stockholders — the Deutsche Boerse agreement allows for discussions in the event the NYSE Euronext receives a proposal that may possibly be superior.

They offered mutual due diligence, and appropriate safeguards so that no competitive risks will be posed to NYSE Euronext, according to the mutually signed document, which also said that the reverse break-up fee is a significant improvement on the Deutsche Boerse agreement and alongside committed financing.

The letter urged the stakeholders that the initial synergies provided by NYSE Euronext/Deutsche Boerse were understated by one-third after two years of exploratory discussions should be carefully considered against the history of NYSE Euronext and Deutsche Boerse failing to deliver promised synergy estimates in their past transactions.

The strategy of NASDAQ OMX and ICE is highly attractive and complementary to the NYSE’s strategy of international expansion and increased operating efficiencies, according to the letter.