Europe's blue-chip shares take biggest one-day tumble in 3 years
* Euro STOXX 50 down 3.7 pct
* Pan-European FTSEurofirst 300 index ends 2.3 pct lower
* Athens ATG index down 5.6 percent on political uncertainty
* Multi-year lows for oil and copper hurt commodities stocks
By Atul Prakash
LONDON, Jan 5 (Reuters) - European equities fell sharply in choppy trading on Monday, with concerns over Greece's future in the euro zone and a steep drop in prices of crude oil and copper hurting financial and commodities stocks the most.
Energy and mining shares were the worst hit. The European oil and gas and basic resources indexes fell 4.9 percent and 3.6 percent respectively after a supply glut sent oil prices to a 5-1/2-year low and copper hit a 4-1/2-year trough due to a stronger dollar.
Investors fear the Jan. 25 election in Greece could vault the left-wing Syriza party into power, raising the risk of a sovereign default.
The euro zone's blue-chip Euro STOXX 50 fell 3.7 percent, the biggest one-day percentage drop since late 2011. Greece's ATG fell 5.6 percent, with National Bank , Bank of Piraeus and Alpha Bank slipping 5.2 to 7.4 percent. Continuación...