FRANKFURT (Reuters) - Germany's financial regulator BaFin has taken a critical view of a settlement between Deutsche Boerse (>> Deutsche Boerse) and Frankfurt prosecutors to clear up a months-long insider trading case, a person familiar with the matter said Friday.

The stance is a blow to efforts by the exchange operator and its CEO to move on from the case, which has cast a shadow over the company since February.

Neither Deutsche Boerse nor the Frankfurt public prosecutor would comment. A court in Frankfurt handling the case said it was not aware of a position by BaFin.

The news was first reported by Bloomberg.

Shares in Deutsche Boerse were down 2.6 percent at 1215 GMT, the biggest loser on the DAX share index of the nation's largest companies.

At issue is a 4.5 million euro purchase of Deutsche Boerse shares made by CEO Carsten Kengeter in December 2015, two months before Deutsche Boerse announced that it was in merger talks with London Stock Exchange (>> London Stock Exchange), which sparked an investigation of possible insider trading.

Last week, Deutsche Boerse agreed to demands to settle the case with prosecutors for 10.5 million euros (£9.29 million). Kengeter would also pay 500,000 euros in a personal settlement.

That settlement is now in the hands of a judge, whose final ruling will be influenced by BaFin's input.

The negative stance from BaFin suggests that the judge may not approve the settlement.

(Reporting by Tom Sims and Andreas Framke; Additional reporting by Hans Seidenstuecker; Editing by Kathrin Jones, Victoria Bryan and Maria Sheahan)

Stocks treated in this article : Deutsche Boerse, London Stock Exchange