I found this picture form a geology camp form the Carpathian Mountains in august 2002. I was called just in time to rescue the bat from the uneducated `locals`...
A knowledgeable friend goes for Myotis mystacinus.
A colleague of mine tells me that you can't rule out at least Myotis alcathoe and Myotis aurescens, and that these can hardly by distinguished based on morphology.