* FTSEurofirst edges back after 1.3 pct rise on Thursday
* Broker downgrade weighs on French broadcaster TF1
By Sudip Kar-Gupta
LONDON, Dec 18 (Reuters) - European shares fell on Friday, retreating from a one-week high reached in the previous session as supermarket group Casino lost more ground following a negative research note.
French TV company TF1 was also among the worst performers, declining by 3.7 percent after brokerage Kepler Cheuvreux cut its rating on the stock to "reduce" from "buy".
The pan-European FTSEurofirst 300 index fell 0.5 percent, while the euro zone's blue-chip Euro STOXX 50 index weakened 0.9 percent.
European stocks had rallied on Thursday as investors took the U.S. Federal Reserve's decision to raise interest rates as a sign of confidence in the world's biggest economy.
Some investors were more circumspect on Friday, pointing to a slowdown in China and weak oil and metals prices as pointing to underlying weaknesses in the global economy.
"I am still quite bearish about the prospects for the first quarter of next year. The oil price problems are not going away any time soon," said Terry Torrison, managing director at Monaco-based McLaren Securities.
Shares in French company Casino fell 3.9 percent, extending Thursday's 11.5 percent after research firm Muddy Waters said it was one of the "most overvalued and misunderstood" companies it had come across.
Casino said on Thursday the report contained "grossly erroneous allegations" that the group would answer in detail.
"Casino is suffering from the knock-on effects of the Muddy Waters article. There have always been some concerns about Casino's levels of debt," said Rupert Baker, European equity sales executive at Mirabaud Securities.
The FTSEurofirst 300 index is up around 4 percent since the start of 2015 but down 14 percent from a peak reached in April.
Economic stimulus measures from the European Central Bank (ECB) have helped underpin European stock markets this year.
Today's European research round-up
editing by John Stonestreet