Milan, January 21 - The Milan stock exchange's FTSE Mib index closed 4.2% up at 18,723 points Thursday after European Central Bank President Mario Draghi said interest rates were set to remain steady for "a long period of time". On Thursday the ECB left its main refinancing rate unchanged at a record low of 0.05%. It also left its deposit rate unchanged at -0.30%. The share price of troubled bank Monte dei Paschi di Siena (MPS) soared back up, taking its capital valuation above the two-billion-euro threshold it had fallen below after coming under extreme pressure in recent days, at 2.14 billion. The MPS share price closed 43.15% up after being suspending several times for excessive volatility - this time of the upward variety, after three days of punishing losses made its accumulated losses this month over 50% despite a recent ban on short selling. Other banks recouped a lot of lost ground too: Carige (+28.843%), Popolare (+10.31%), Unicredit (+7.93%), whose repurchase of 1.8 billion euros was hailed by the stock market, Bper (+11.04%), Ubi (+5.69%) and Bpm (+4.37%). The banking sector's recovery tugged the rest of the list in its wake: Mediaset (+6.14%), FCA (+6.37%), Exor (+4.4%), Telecom (+5.38%) and Ferrari (+3.59%). Only two blue chips fell: Ferragamo (-0.4%) and Saipem, which dropped 5.87% amid uncertainty over a 3.5-billion-euro rights issue whose details will only become clear on Monday. The other main European bourses, London, Frankfurt and Paris, posted gains of under 2%.