Embattled Russian billionaire Oleg Deripaska will return his 25% stake in Austria’s Strabag construction company to its shareholders, Deripaska’s Basic Element holding company told the Moscow Times on Monday. One of the biggest Russian casualties of the global economic crisis, Deripaska is estimated to have lost $25 bn (EUR19.12 bn) of his fortune over the past year as his business empire came under intense financial pressure.