Insider trading probe into Deutsche Boerse CEO still open - prosecutor

* Premature to say CEO Kengeter is off the hook

* Regulator is investigating potentially misleading Deutsche Boerse statement earlier in week

* Deutsche Boerse (IOB: 0H3T.IL - news) says on Thursday proceedings are "ongoing" (Updates with background, BaFin comment)

FRANKFURT, July 20 (Reuters) - Deutsche Boerse chief executive Carsten Kengeter has not yet been exonerated from insider trading allegations, officials said on Thursday.

On Tuesday, a public statement from Deutsche Boerse spoke of a deal from the Frankfurt prosecutor in which Kengeter would be cleared of any wrongdoing and the exchange operator would be fined 10.5 million euros ($12 million).

However, a spokesman for the public prosecutor in Frankfurt on Thursday said the investigation was "open", and a spokesman for Deutsche Boerse said the proceedings were "ongoing".

The German markets watchdog BaFin is now investigating whether Deutsche Boerse's statement misled the public.

Earlier this year, as Deutsche Boerse discussed a merger with the London Stock Exchange (Other OTC: LDNXF - news) , police and prosecutors searched Kengeter's office and home amid concerns over Deutsche Boerse share purchases made months before the announcement of merger talks.

Kengeter has always denied allegations of wrongdoing, saying the purchases were part of an official Deutsche Boerse compensation plan. "Insider trading goes against everything I stand for," he told shareholders in May.

The fines of 10.5 million euros imposed upon Deutsche Boerse would be for failing to notify the public in a timely way about the merger talks with the LSE and for the design of its executive share-buying scheme that allowed Kengeter to buy shares in the first place.

($1 = 0.8698 euros) (Reporting by Hans Seidenstuecker, Alexander Huebner and Tom Sims; Editing by Edward Taylor and Elaine Hardcastle)