Russian oil company Tatneft has filed a $1.1 billion suit against Ukraine in an international court in a refinery ownership dispute, a company source said on Wednesday, according to Reuters.

"The suit has been filed today in accordance with arbitration procedures of the United Nation`s international trade commission. The suit is for $1.1 billion and the amount can increase," the source told Reuters.

In October, Tatneft suspended supplies to Ukraine`s Kremenchug refinery after the plant`s former manager Pavel Ovcharenko used armed police to oust managers friendly to Tatneft, citing a court order to reinstate him.

Tatneft has called on the government of Ukraine to help it resolve the dispute as required by an inter-governmental agreement on bilateral investment protection, but has said Kiev has never replied to its calls.

"We are filing the suit because of the company seizure in October 2007 which made it impossible for the Russian shareholders to manage the plant," the source said.

"We have been waiting for a few months for Ukraine to take constructive steps and start talks. But because it never happened, we are using our right to file the suit."

He said the arbitration will likely take place in Zurich. The government of Ukraine was not immediately available for comment.

Tatneft had been the key supplier to Kremenchug before the dispute and the plant has been forced to buy crude from Belarus and even Iraq to maintain processing levels since October.

Reuters, Guardian