Deutsche Boerse shares rose the highest level in nearly two years Monday as investors bet that Europe's biggest stock exchange group could be a possible takeover target of the US-based CME Group, according to media reports first issued by Bloomberg.

Shares in the Frankfurt stock exchange owner surged nearly 11 percent to change hands at €51.66 each, the highest level since August 2011, before trimming gains after the company issued a statement on its website that challenged the story.

"Deutsche Börse AG is not in merger negotiations with CME Group, the statement read. "As repeatedly communicated, Deutsche Börse Group's primary strategic focus is on organic growth, mainly by expanding its business into growth regions in Asia, extending its services for unsecured and unregulated markets, and expanding its combined market data and IT business."

The CME Group is the world's largest futures exchange and has a market value of around $19.4bn (£12.8/€14.6) compared to around $11.9bn for Deutsche Boerse.

The group posted 2012 net income of €660m earlier this month on revenues of around €1.93bn while announcing plans to trim around 250 jobs through a €30m restructuring programme. Last year, Frankfurt-based Deutsche Boerse was blocked from its to buy NYSE Euronext in $9.3bn deal that the European Commission said would have created a "near monopoly" in the market for financial derivatives. Deutsche Boerse CEO Reto Francioni called the decision a "black day for Europe and its global competitiveness on financial markets."

The Intercontinental Exchange made an $8bn approach to buy NYSE Euronext on 20 December, confirming earlier media reports that linked the owner of the world's most famous stock exchange to a second takeover attempt. The Atlanta-based group, known as ICE, will pay $33.12 for each NYSE Euronext share in a deal that values the Big Board operator at around $8.2bn.

ICE said NYSE Euronext shareholders will own around 36 percent of ICE shares once the deal is complete. It also said it will look to spin-off the Euronext portion of the company through and initial public offering but will keep the NYSE brand intact. Duncan Niederauer will be named as president and CEO of the combined group, the statement said.

ICE's previous bid for the Big Board operator - an $11bn approach made with Nasdaq OMX in April 2011 - was rejected by the US Justice Department which feared the tie-up would reduce the amount of new American listings on the jointly owned exchange.