Austria's financial regulator extended a ban on naked short selling for some Austrian financial institutions until May 31, 2012, the Austrian Financial Market Authority said Tuesday.

The ban on naked short selling, which was due to expire Nov. 30, applies to shares in Austrian lenders Erste Group Bank AG (EBS.VI) and Raiffeisen Bank International AG (RBI.VI), and Austrian insurance companies Uniqa Versicherung AG (UQA.VI) and Vienna Insurance Group (VIG.VI).

-By Nicole Lundeen, Dow Jones Newswires; +43 1 513 6922 11; nicole.lundeen@dowjones.com