Auckland, the largest city of New Zealand, has tied with Vancouver to be the fourth most livable city in the world in the Mercer 2010 Quality of Living Survey.

It's the highest ranking for any city in the Asia Pacific region, beating out Sydney (10th) and Melbourne (18th).

Wellington takes the 12th spot and comes fifth in the eco- ranking category, which ranks cities based on water availability, water potability, waste removal, sewage, air pollution and traffic congestion. Auckland comes 13th in that category, which Calgary takes the top spot in.

Georgina Harley, of Mercer, said New Zealand and Australian cities cemented their place as favourable destinations for multinationals expanding or establishing a business within the Asia-Pacific region.

"The consistently high quality of living ranking of our cities ensures New Zealand and Australian continue to be attractive and viable destinations for both employers and employees."she said.

Vienna retains the top spot as the city with the world's best quality of living. Zurich and Geneva follow in second and third position, respectively.

Baghdad comes in last.