Russian investor Victor Vekselberg Thursday was acquitted by the Swiss federal criminal court of having breached the country's bourse rules, escaping a potential 40 million Swiss franc fine that risked souring relations between Russia and Switzerland.

Vekselsberg, who leads Russian investment firm Renova Group, had been charged by the Swiss finance ministry and the Swiss financial market supervisory authority to have built an illegal shareholder group together with two Austrian businessmen in their pursuit of taking over a controlling holding in Swiss industrial conglomerate OC Oerlikon AG (OERL.EB).

Switzerland's federal criminal court, however, found no evidence the investors formed a group to jointly gain control of Oerlikon. Renova and Victory, the company headed by Austrian investors Ronny Pecik and Georg Stumpf, own a majority stake in the Swiss firm of about 49.6%. They started to build up their stake in 2006, when the company was known as Unaxis AG.

The Austrian businessmen had also each faced a 40 billion Swiss franc fine; both were also acquitted.

The finance ministry's charge and its unusual push for a massive fine for the Austrian and Russian investors--the highest ever demanded in Switzerland--risked undermining relations between Switzerland and Russia, where many large Swiss corporations are active.

In January, Russia's finance minister Alelxei Kudrin had said that the large fine levied against Vekselberg risked creating tensions between the two countries and may lead to "a number of uncertainties, which cause a sensitive reaction of the Russian government."

In the wake of the row, Swiss food and beverages giant Nestle SA (NESN.VX) had been denied permission to import baby food products in Russia. Airline Swiss, a unit of Deutsche Lufthansa AG (LHA.XE), had difficulties obtaining permission to fly over Russia on its route to China.

Although hailed by many as a potential savior of Switzerland's industrial sector, Vekselberg's arrival in Switzerland had been marked by a series of critical media reports that questioned the billionaire's business practices.

Vekselberg's rationale for taking over and building up large stakes in Swiss industrial firms such as Oerlikon, oil and gas supplier Sulzer AG (SUN.EB) and textile machinery producer Rieter Holding AG (RIEN.EB) had also been scrutinized. Many feared the billionaire would handle the holdings as pure investments and split up the companies and slash thousands of jobs.

Vekselberg, who couldn't be reached for comment Thursday, had repeatedly said that his investments in Switzerland were meant to tap the large business opportunities offered by the companies. Still, his investments in firms such as Oerlikon, which is currently suffering from the global economic downturn, have so far failed to produce the hoped-for returns.

Renova, meanwhile, said the ruling by the Swiss criminal court showed that the transactions regarding Oerlikon represented "nothing more than the normal market behavior of two independent shareholders." Pecik and Stumpf couldn't be immediately reached to comment further.

The Swiss finance ministry, meanwhile, hasn't decided whether it would appeal, a spokesman said, noting the next step would be the Swiss federal court, Switzerland's highest. A similar case involving Vekselberg's investment in Sulzer is still pending. Renova holds a stake of about 31.2% in the firm.

-By Goran Mijuk, Dow Jones Newswires, +41 43 443 80 47; goran.mijuk@dowjones.com