VIENNA (AFP)--Austrian financial authorities said Wednesday they were investigating the head of oil and gas giant OMV AG (OMV.VI) on suspicion of allegedly manipulating the company's share price.

"We have opened a preliminary investigation against (Wolfgang) Ruttenstorfer," a spokesman for the Financial Market Authority, or FMA, Klaus Grubelnik, told AFP.

The spokesman confirmed a report in business daily Wirtschaftsblatt, which said Ruttenstorfer was under investigation on suspicion he may have manipulated OMV's share price when the company was seeking to sell its stake in Hungarian rival MOL Nyrt. (MOL.BU) earlier this year.

According to Wirtschaftsblatt, Ruttenstorfer bought EUR620,444 of OMV shares on March 23.

In an interview with the weekly magazine Profil the same day, the CEO had insisted OMV intended to hold on to its 21.2% stake in MOL "for the rest of the year," even though it had failed in its bid to fully acquire the Hungarian group.

Subsequently on March 30, OMV sold its stake in MOL to Russian group Surgutneftegas for EUR1.4 billion. The announcement sent the Austrian company's share price up 3.3% to EUR25.10 on a day when the Vienna stock exchange was showing a loss of 4.2%. The value of Ruttenstorfer's shares increased by nearly EUR45,000.

OMV said it would cooperate fully with the FMA with regard to the enquiry into the sale of its stake in MOL to Surgutneftegas.

"As a publicly listed company, we abide by all laws, rules and international standards of good corporate governance," it said in a statement.

With regard to Ruttenstorfer's share purchase on March 23, OMV said: "The legal conditions and timeframes under which managers can buy or sell shares - so-called directors' dealings - are very clearly defined. All of these rules and conditions were and still are being met."

The Austrian giant was forced to abandon its plans to take over MOL in face of opposition from the Hungarian government and objections on the part of the European Union.

Ruttenstorfer has been CEO since 2002 and is scheduled to step down on March 31, 2011. On the stock exchange Wednesday, OMV shares were showing a gain of 0.21% at EUR24.12.