A Russian court has ordered a Norwegian telecom to give up a nearly 30 percent stake it holds in a Russian telecom, rattling already nervous Russian investors. Markets fell on the news.

The Norwegians charge the court decision is simply giving up the company to Russian billionaire Mikhail Fridman, who jointly owns VimpelCom, the cellular operator in question.

Telenor, the Norwegian company, contends that Farimex Product is really a front for Mikhail Fridman.

The court ruling follows a February ruling which required Telenor to pay $1.7 billion in damages for delaying VimpelCom’s takeover of a Ukranian mobile phone provider in 2005. Telenor challenged that order as well.

The confiscation of the stake “is yet another escalation of the attempts to steal our VimpelCom shares with the aid of Russian courts,” Jan Edvard Thygesen, Telenor’s head of central and eastern Europe operations, said in a statement.

Telenor said the VimpelCom shares were seized as a “retaliation” shortly after a U.S. court ruled to fine Altimo, Alfa’s telecommunications unit, for not obeying a 2008 decision, which ordered it and its affiliates to sell their interest in Ukrainian cell company Kyivstar within 90 days.