LONDON (REUTERS) - Melbourne was named the world's most liveable city for the third year in a row, according to a survey of 140 cities released this month by the Economist Intelligence Unit (EIU).

The survey ranked the Syrian capital Damascus least liveable.

Melbourne, capital of Australia's south-eastern state of Victoria, beat out Vienna, followed by Canadian cities Vancouver, Toronto and Calgary. Australia's Adelaide, Perth and Sydney also made it into a top 10 list which included the Finnish capital, Helsinki, and Auckland, New Zealand.

"We feel immensely proud that Australia's fastest growing city has again been recognised as the most liveable city in the world," Agent-General for the Victorian Government in Britain Geoffrey Conaghan said in an emailed statement.

The survey ranked Melbourne first among cities based on five categories of stability, healthcare, culture and environment, education and infrastructure, while highlighting the decline of Damascus, alongside Egypt's Cairo and Tripoli in Libya, as a result of civil unrest across the Middle East and North Africa.

Unrest since Arab uprisings in 2011, which led to civil wars in Syria and Libya, as well as upheaval in Egypt, have pushed Damascus, Tripoli and Cairo down the rankings in the annual survey. Damascus dropped 10 places from last year to hit bottom.

"While the threat of terror had a defining influence on liveability in the last decade, we can clearly see that civil unrest has already had a significant impact on liveability in this decade," survey editor Jon Copestake said in a statement on the EIU website.

The survey excludes cities such as Kabul in Afghanistan and Baghdad in Iraq, long plagued by conflict and insecurity.

Damascus, once regarded as a relatively secure city in the Middle East, had been a growing tourist destination before an uprising against Syrian President Bashar al-Assad in 2011.

On Wednesday, residents were bracing for possible Western military action in response to a poison gas attack which killed hundreds of people in the city's suburbs a week ago.

Other cities placed in the bottom 10 in the liveability survey included Dhaka in Bangladesh, Lagos in Nigeria, Libya's Tripoli, Port Moresby in Papua New Guinea and Harare in Zimbabwe.