Mikhail Fridman has won some of the fiercest battles in Russia's corporate history but his five-year row with Norway's Telenor comes to a head on foreign soil, as his fortune shrinks in the global downturn.

Fridman, a stocky man with twinkly eyes and a chess player's genius for risky gambits, started with investors on his side in the dispute with Telenor over claims the latter was holding back their mobile joint venture Vimpelcom in the lucrative Ukrainian market.

But as the five-year old hostilities with Telenor escalated sharply on Thursday, Russian shares fell as investors feared the latest in a string of corporate bust-ups.

If there is a significant drop in the price or damage to the company because of this, there could be some retail-level investor lawsuits, Valartis fund manager Tim McCarthy, who manages $850 million in Eastern Europe, said.

This is a different case from TNK-BP, referring to Fridman's last high-profile battle with oil major BP, in which analysts declared Alfa and its partners the winners as the British company acquiesced to many of their demands on management and strategy changes.

Alfa's hand is also weaker this time. Listed in Forbes magazine this week as the fourth-richest Russian, Fridman's estimated fortune is $6.3 billion, a third of what it was a year ago.

Bailiffs seized Telenor's stake in Vimpelcom late on Wednesday, just hours after a U.S. court held Fridman's Alfa Group in contempt for failing to comply with an order to give up its Ukrainian telecoms assets.

NO EVIDENCE OF GOOD FAITH

Alfa has spent the past decade in episodic skirmishes, showing no fear of challenging rivals foreign and domestic.

BP was forced to write down its first big investment in a Russian company in 1999 when key production assets were bankrupted and sold to Alfa-controlled oil company TNK.

A few years later, a tie-up between BP and TNK in Russia was hailed as a start to a new era in corporate governance and a sign that the rough-and-tumble of the 1990s had come to an end, but the two sides found themselves waging war again last year.

Analysts hold out hope the escalation of the conflict with Telenor signals a resolution may be near, as it did in Alfa's last bout with BP. If this is the case, it is seen as likely Alfa will swap its Kyivstar stake for Telenor's shares in Vimpelcom, and they would part ways.

But Fridman's reduced cash resources could leave him unable to make up the difference between Alfa's Kyivstar stake and Telenor's more valuable stake in Vimpelcom, analysts say.

His bank, Alfa Bank, is suing businesses controlled by indebted aluminum tycoon Oleg Deripaska to reclaim over $1 billion in unpaid loans, a bank executive said this week [ID:nLB941862].

And while many of Fridman's previous battles played out in Siberian courts in lawsuits filed by third parties, he is largely fighting this battle in a U.S. court.

Alfa Group's lawyer drew a sharp rebuke from the U.S. judge who issued a contempt ruling on Wednesday for failing to comply with orders to sell its holdings in Kyivstar, a transcript of the hearing showed.

There has been no evidence of good faith compliance, Judge Gerard Lynch told an Alfa lawyer who asked him to stay the ruling. Any further delay is unacceptable.

(Editing by Erica Billingham)