Skyscrapers border the lush green landscaping in Shenzhen's central business district. (Photo: chinadaily.com.cn)

A ranking of global cities based on connectivity in their production and service industries was released on Friday on the website of the Globalization and World Cities (GaWC) Research Network, a think tank at Loughborough University in the United Kingdom.

Cities were divided into four major levels — alpha, beta, gamma and sufficiency — based on how six production service agencies involving banking, insurance, law, consultative management, advertising and accounting are stationed. More than 700 cities worldwide were evaluated.

In the 2020 World City List, six Chinese cities were listed among alpha-level global cities, the first tier. Of the six, Hong Kong, Shanghai and Beijing were listed as Alpha-plus cities, while Guangzhou, Taipei and Shenzhen were selected as Alpha-minus.

In addition, 12 Chinese cities across the country were listed as beta-level global cities, the second tier. Zhengzhou, Henan province, and Xi'an, Shaanxi province, were shortlisted to the rank of beta-minus city for the first time, and Chongqing was raised from beta-minus to beta level.

The GaWC think tank has released the world city rankings every two or four years since 2000. Eight world city rankings have been published, with the latest released on Friday.