(ANSA) - Rome, August 10 - Italy's civil aviation authority Enac on Friday threatened to revoke Sicilian low-cost carrier Windjet's operating licence on Monday in the absence of improvements to services. Recently the near-bankrupt airline has been forced to cancel numerous flights while many others have been subject to long delays. Earlier in the day airline representatives failed to attend a meeting with Enac officials for the second day running to discuss the problems. In a statement the authority called on Windjet to "implement with immediate effect an emergency plan to ensure the full efficiency and punctuality of flights" and to make the payments owed to management companies, baggage handlers and other service providers on pain of seeing its planes grounded from Monday onward. Enac also invited the company to suspend ticket sales until normal services have resumed. Windjet is in negotiations with national flag carrier Alitalia for a takeover. On Friday Alitalia said it was still open to completing a deal provided the low-cost company furnished missing guarantees. The airline also said it was prepared to bring the closing date forward to August 20 from the scheduled date of August 31.