* German court says Woolworth Germany files for insolvency
* Frankfurt district court appoints interim administrator
* Administrator says business will carry on as usual
* Woolworth 2007/08 sales about 900 million eur
(Adds comments from administrator and background)
FRANKFURT, April 14 (Reuters) - German department store chain DWW Woolworth GmbH & Co, owned by British investor Argyll Partners, filed for insolvency, a court said on Tuesday.
The Frankfurt district court appointed Ottmar Hermann as interim administrator, a court spokesman said.
Slow Christmas sales, increasing competition, weaker sales at its discount operations and insufficient liquidity led to insolvency, the administrator said in a statement.
Business at its roughly 300 German and 20 Austrian stores would continue as usual, Hermann said, adding both the Austrian and logistics operations were not affected by the filing.
U.S. retailer F.W. Woolworth founded its German subsidiary in 1926 and opened its first store in the northern German city of Bremen in 1927.
The unit split from its parent in 1998 in a management buyout and since 2007 has been owned by Argyll Partners.
Woolworth employs about 9,000 staff in Germany and generated about 900 million euros ($1.2 billion) in sales in its fiscal year to end-October 2008.
The news comes just months after Britain's Woolworths -- an offshoot of the former U.S. retailer -- went into administration in November. The chain's 807 stores, which operated independently from 1982, were closed by Jan. 5 with the loss of about 27,000 jobs.
Former U.S. parent Woolworth Corp, which started the five and dime stores in 1879, closed its remaining stores in 1997, changing its name later to Venator and in 2001 to Foot Locker.
Retailers around the world are suffering as the global economic downturn spoils consumer spending amid rising unemployment. Refinancing has also become increasingly difficult as a result of the financial crisis.
Department stores in particular are struggling as customers prefer to shop at discounters or specialist shops.
Arcandor, whose German department store chain Kartstadt posted an operating loss of 272 million euros in 2007/08, is now looking into applying for state aid. (Reporting by Alexander Huebner and Nikola Rotscheroth; Writing by Eva Kuehnen; Editing by Michael Shields and Andrew Macdonald) ($1=.7574 Euro)