(Updates prices, adds detail)
* FTSEurofirst 300 down 0.4 pct, FTSE 100 down 0.5 pct
* Weak oil and metals prices weigh on markets
* Ocado falls on concerns of competition from Amazon
By Sudip Kar-Gupta
LONDON, Dec 30 (Reuters) - European stock markets fell on Wednesday as weak commodity prices impacted the shares of mining and energy companies.
Online supermarket group Ocado also underperformed, with its shares sliding on concerns over growing competition from a rival service at Amazon.
The pan-European FTSEurofirst 300 index and the euro zone's blue-chip Euro STOXX 50 index both declined by 0.4 percent, surrendering ground after rising in the previous session.
Britain's FTSE 100 index of leading shares fell 0.5 percent while Germany's DAX retreated by 0.8 percent.
"The ongoing weakness in the oil price is dragging down the markets," said John Plassard, senior equity sales executive at Mirabaud Securities.
Brent crude oil slid back towards 11-year lows on Wednesday as indications of slowing global energy demand bumped up against record-high inventories.
Crude prices have plunged by two-thirds since mid-2014 as soaring output from the Organization of the Petroleum Exporting Countries, Russia and the United States led to a global surplus of between half a million and 2 million barrels per day.
This caused the shares of oil companies such as BP and Total to fall, while British mining stocks also slid lower as metal prices fell due to persistent concerns about a slowdown in China, the world's biggest consumer of metals.
Spreadex analyst Connor Campbell added that a warning by the head of the International Monetary Fund in a newspaper column of disappointing global economic growth next year was adding further pressure on the markets.
Britain's FTSE is down around 4 percent since the start of 2015, having lost ground from a record high reached in April.
However, stock markets in continental Europe have fared better, thanks partly to economic stimulus measures from the European Central Bank.
The FTSEurofirst 300 is up around 6 percent in 2015, while the DAX is up 10 percent.
Today's European research round-up (Editing by Toby Chopra)