The companies confirmed that they received the document detailing the European Commission's concerns over Deutsche Boerse's $9 billion purchase of NYSE Euronext.
In a statement issued after the close of the European trading day, the companies emphasized that the statement of objections is a normal phase in the second stage of a merger procedure setting out the provisional position of the Commission, "and does not prejudge the final outcome of the case."
They added: "We continue to strongly believe that our combination provides substantial capital and and cost savings to users; advances the goal of a unifie, liquid EU capital market for raising money and managing risk; and does not materially alter the competitive landscape."
The companies also pledged to continue to work closely with investigators.
The EC has until Dec. 13 to complete its inquiry. Although the objections were not made public, regulators identified problems in several areas when they opened the in-depth probe this summer - notably in derivatives trading, where the merged entity would be "by far" the market leader.
EU Competition Commissioner Joaquín Almunia has also said publicly that within this "crucial sector," regulators would continue to look at the impact that financial-market mergers would have on competition in market data, indexes, trading technology, access to collateral, clearing and settlement,
Sending a confidential statement of objections is standard procedure in in-depth competition probes. Now that the two exchanges have the document, they can begin to consider possible remedies to appease regulators' concerns.
In a research note Thursday, analyst Philipp Hässler of Frankfurt's Equinet Bank, said the main risks are that the new company will be forced to give up part of its derivatives business - such as by selling Liffe - or by opening its clearinghouses to other trading venues.
Within several weeks, the Commission is expected to follow usual procedure and send non-confidential copies of the document to third-party complainants.
There's a surprising face in the line of government officials heading to the private sector: Sharon Cohen Levin, "the Babe Ruth of Forfeiture." For other updates launch today's Movers & shakers slideshow.
The semiconductor equipment makers ran into trouble with the Department of Justice over competition issues. More video