Departures and arrivals at the airport will now be suspended until 6:00am local time (0400GMT) Tuesday, the operator said on its website.
The closure was due to "falling volcanic ash" caused by the eruption, it said.
Earlier Monday, the airport management said that flights in and out of the airport would be halted until 1:00 pm, before extending that until 8:00 pm.
Catania's Mayor Enrico Trantino on Monday prohibited the use of motorcycles and bicycles in the city for 48 hours, "because several areas are covered with a layer of volcanic ash", city hall said on its website.
The ash can quickly become slippery on roads and increase the risk of accidents.
At 3,324 metres (nearly 11,000 feet), Etna is the tallest active volcano in Europe and has erupted frequently over the past 500,000 years.
Most recently, Catania airport was closed for a day on May 21 due to an eruption.
Around 10 million passengers last year transited through the airport, which serves the eastern part of Sicily.
The closure hits during Italy's busiest tourist season and a day before the August 15 national holiday.
Related Links
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest
Subscribe Free To Our Daily Newsletters |
Subscribe Free To Our Daily Newsletters |