Europe shares extend sell-off; BES tumbles again
(Recasts with closing levels, details, quotes)
* FTSEurofirst 300 down 1.2 pct, hits 3-1/2 month low
* Portugal mulls use of state funds to help Espirito Santo
* Investors rattled by Argentina's default, Russian sanctions
* DAX breaks below key level in huge trading volumes
By Blaise Robinson
PARIS, Aug 1 (Reuters) - European stocks sank in huge volumes on Friday for the third straight session, with a broad index hitting a 3-1/2 month low, hurt by concerns over losses at Banco Espirito Santo as well as tension between Russia and the West.
Shares in Banco Espirito Santo sank 40 percent, adding to its 42-percent plunge on Thursday when the bank posted a 3.6 billion euro loss and higher-than-expected provisions to cover its exposure to companies owned by its founding Espirito Santo family.
The massive loss at the Portuguese lender has dragged Europe's banking sector index down 3.5 percent this week, reviving concerns over the sector, particularly in southern Europe, hit hard by the years-long sovereign debt crisis. Continuación...