* Interest in objects owned by empress remains strong
* Two cigars fetch 34,500 euros, lock of hair 15,000 euros
By Derek Brooks
VIENNA, April 30 (Reuters) - A riding hat believed to have been worn by Austro-Hungarian Empress Elisabeth, called "Sisi" by family and friends, fetched 134,500 euros ($186,500) at a Vienna auction, more than 50 times higher than expected.
Elisabeth was the wife of Emperor Franz Joseph I, a selection of whose personal items were also highly sought-after at Wednesday's sale of imperial memorabilia.
"The hat I think is the most interesting object, although we are not sure if it belonged to Sisi or her daughter," said Georg Ludwigstorff, the auction specialist in charge.
"There is always high interest in the Habsburgs' personal items - especially those of Elisabeth," Ludwigstorff said.
The auction at Austria's Dorotheum took place as Vienna prepares to mark 100 years since the June 28, 1914 assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, which lit the fuse for World War One.
Katrin Unterreiner, curator of the Plachutta Kaiserhaussammlung, the biggest private Habsburg imperial collection, was thrilled to acquire Sisi's ermine muff for 3,750 euros.
"I was very surprised. I actually excepted it to go higher. But that's the exciting thing about auctions. You never know what will happen," Unterreiner said.
Sisi, a beauty and free spirit who continues to intrigue biographers, novelists and film makers, was assassinated by an Italian anarchist in 1898.
Beyond her riding hat, a sketch that the 10-year-old future empress drew of a child hugging a dog sold for 11,000 euros, while her dinner bell fetched 15,000 euros.
Elements of her wardrobe, including a collection of ermine garments, are on display in Vienna at an exhibition commemorating the 10th year of the Sisi Museum.
Personal items belonging to Emperor Franz Josef also commanded higher-than-estimated prices.
Unterreiner bought for the Plachutta collection two of the emperor's imperial cigars for 34,500 euros, 16 times their expected price.
A lock of his blond hair, taken from future emperor at the age of three, was hotly contested, reaching 15,000 euros. His monogrammed imperial underpants barely surpassed the reserve price at 2,500 euros.
The assassinated archduke's cigarette lighter and case fetched 2,750 and 4,000 euros respectively.
Around 200 items were on sale at the Dorotheum, founded in 1707 and the largest auctioneer in continental Europe. It conducts an annual sale of imperial memorabilia.
($1 = 0.7212 Euros) (Editing by Michael Roddy and Grant McCool)