The Russian anti-trust regulator has welcomed the news that locally-controlled Alfa Group has raised its stake in VimpelCom, bringing its shareholding in line with Telenor, but has not yet officially withdrawn its legal action against the Norwegian firm.

Last week, Alfa Group, owned by Russian billionaire Mikhail Fridman, increased its voting stake to 40.5 percent from 25 percent after buying US$3.6 billion in shares from another VimpelCom shareholder, Weather Investments.

"We welcome the increase by [Alfa Group unit] Altimo of its stake in Vimpelcom because it leads to the Russian shareholder restoring control in the strategic Russian company," FAS, the anti-monopoly regulator, sad in an emailed statement to Reuters.

With Alfa bringing its stake closer in line with Telenor’s, the Russian firm has agreed to drop a legal challenge against an earlier stake increase by the Norwegian operator. However, according to Reuters, FAS said it was too early to talk about withdrawing its own lawsuit, which had prompted a Moscow court to issue an injunction preventing VimpelCom from paying dividends.

Although VimpelCom is headquartered in Amsterdam, its Russian unit generates 40 percent of group sales and is considered a strategic Russian asset, meaning it is up to the government to decide whether a foreign investor may raise its stake above a 25 percent threshold.

Telenor also acquired Weather shares last week to lift its stake to 43 percent from 39.5 percent. It is understood that Alfa has asked Telenor to sell some of its stale to maintain equal parity between the two shareholders.