National Joint-Stock Company Naftogaz of Ukraine has sent a formal notification on investment dispute over the assets in the annexed Crimea to Russia, the company’s press service reports.

“Naftogaz of Ukraine handed over a formal notification to the Russian Federation with regard to the investment dispute within the framework of a bilateral agreement on mutual protection of investments between Russia and Ukraine,” reads the statement.

Specifically, the dispute was caused by the unlawful seizure of Naftogaz investments into the peninsula by Russia.

“In accordance with the terms of the agreement, Naftogaz has sent a formal request for consultations and negotiations with representatives of the Russian Federation in order to settle the dispute,” the company’s press service noted.

According to the report, if the dispute is not resolved through negotiations, it will be submitted to arbitration.