Supplying energy technology to Crimea flouts sanctions imposed by the European Union following Russia's 2014 annexation of the region. However, Russian President Vladimir Putin has vowed to ensure stable energy supply for the peninsula.

"Over the last few months, our customer has confirmed to us numerous times in writing that a delivery to Crimea would not occur. As a consequence, Siemens will initiate criminal charges against the responsible individuals," it said on Monday.

(Reporting by Georgina Prodhan; Editing by Edward Taylor)