Milan, January 28 - Shares of Monte dei Paschi di Siena (MPS), Italy's third-largest lender, gained 6% to 0.27 euros in early trading on Monday, with 20 million shares changing hands over the course of just minutes. On Friday, the troubled bank gained 11.36% with volume reaching 12% of its capital. The stock bounced back after losing 20% of its value over the preceding three days. Last week, news broke that loss-making derivatives trades could cost it as much as 720 million euros. The news led to the resignation of MPS ex-chairman Giuseppe Mussari from his post as chairman of the Italian banking association ABI the same day. The European Commission is in contact with Italian authorities over the unfolding of the derivatives scandal. In December the commission gave provisional backing to a 3.9-billion-euro government bailout for the historic bank "to preserve the stability of the Italian financial system," said a Brussels spokesman. On Friday a special MPS shareholders' meeting approved recapitalisation aimed at paying back bonds issued for the bailout. If the bonds are not repaid the government will take stock in MPS. The Bank of Italy OK'd the bond scheme on Saturday. Also on Friday the MPS banking foundation, the bank's majority shareholder, said it may take legal action against those deemed responsible for the derivatives-trading losses the bank is currently facing.