Big stock exchange mergers are currently off the table for German stock exchange operator Deutsche Boerse after a failed attempt to link up with London Stock Exchange, CEO Carsten Kengeter said today. 

"It is currently quite difficult to think about large exchange mergers," Kengeter told shareholders at the company's annual general meeting. 

"But that does not mean acquisitions, partnerships, and investments are no longer possible," he added. 

Kengeter also said allegations of insider trading against him will prove unfounded and that he was cooperating with authorities in the matter. 

Following the failed LSE merger, Deutsche Boerse now aims to extend its trading platforms to a broader range of assets. 

Kengeter pointed to foreign-exchange as particularly promising, along with energy, raw materials and other commodities trading. 

In May, Deutsche Boerse's energy exchange platform EEX bought the US electronic commodities exchange Nodal. "A promising market indeed," Kengeter noted. 

Kengeter has been under pressure following the unsuccessful merger with LSE. 

In addition, Frankfurt public prosecutor's office is investigating whether Kengeter used non-public information for personal gain in his own share trading. 

"These allegations have deeply concerned me personally, because this is exactly what I did not do," Kengeter said. 

"Deutsche Boerse, as well as myself personally, are fully cooperating with the public prosecutor's office, and I am certain that, following detailed investigation, the allegations will turn out to be unfounded," he added.